10 ways to make the most of conferences as a PhD student

Ah conferences. Probably held in a relatively picturesque location, full of exciting, cutting edge science and a stressful timesink for anyone unlucky enough to be saddled with the actual organization.

Participants in the "Three Elephants in the Gamma Ray Sky" conference, Garmisch-Partenkirchen, Germany, October 2017

Participants in the "Three Elephants in the Gamma Ray Sky" conference, Garmisch-Partenkirchen, Germany, October 2017

I've been to a few conferences now as a student, and most of them have been productive and good experiences. Here are 10 things I've learned from by (abeit brief) time attending conferences:

Pre-Post-Script: Thanks to Ángel López-Sánchez on Twitter for reminding me of the thing I forgot to write here. Conferences can be stressful and, depending on the individual, can be quite taxing emotionally. Many, many people (more than you might imagine. Yes, even the individuals who appear gregarious and outgoing) struggle with aspects of the social parts of conferences. Even for extroverts (in so much as people can be divided into those favoring introversion or extroversion) need alone time, which can be a precious commodity at a 5 day conference with constant activities lined up. For those who have met me, it may surprise you that at my first conference, it took me a day and a half to talk to anybody other than my supervisor. I, like many other people I know, cover up any social anxiety by working hard to be outgoing and friendly. 

Nobody should ever be made to feel guilty or like a bad scientist if they need some time to retreat to their hotel room. I'm a big proponent of providing quiet spaces for people to sit in, where there is a rule that you do not approach people sitting in the quiet space. If you need a break at a conference, don't be afraid to say "I need a break, I will be back later", and take some time out for yourself. Constantly pushing yourself to breaking point will a) make the conference less enjoyable and b) possibly put you off conferences. Also, if you're organizing conferences, please reconsider requiring/forcing students (or anybody really) to share rooms. From talking to other students, not having a private refuge can cause excessive stress at conferences.

Lone Pine Koala Sanctuary in Queensland fences off part of the area where tourists can interact with, pet and feed their kangaroos and wallabys, providing a safe area the animals can rest away from humans. Perhaps your next conference should provide…

Lone Pine Koala Sanctuary in Queensland fences off part of the area where tourists can interact with, pet and feed their kangaroos and wallabys, providing a safe area the animals can rest away from humans. Perhaps your next conference should provide a scientist rest area, where individuals can sit and work quietly without being disturbed.

 

1. Do your research before you arrive

Not your research research (but do that too, science is important), but sit down and have a good look at who is giving talks and who the other conference participants are. Are there any people on the participant list whose work you often cite? People whose ideas complement or clash with your own? Someone you'd like to collaborate with or a future employer? Make a list of people you want to introduce yourself to, and think of some starter questions to ask the  (going through abstracts of their recent papers can be a good start). This eliminates the need to think up awkward small talk on the spot, and also helps with the next point...

2. Make contact before the conference starts

The bigger the name you'd like to talk to at the conference, the more people they will probably have to talk to. If you are interested in talking to someone on your list face to face, it can be a good idea to contact them via email before the conference, briefly introduce yourself and state that you are going to conference x, and would they have some time to set aside during a break to briefly chat. The email should only be a maximum of 2-3 sentences long, polite and not rambling. If you have met someone previously and wish to sit down and discuss science with them again, it's also a good idea to let them know you'll be attending said conference. Planning a meeting before the conference, when people are often busy, gives you a much higher chance of actually having the conversations you want.

3. Try to give a talk

Conferences are for showing off your work, and other than papers are one of the primary ways of disseminating information about your research. Often, people will remember conference talks better than actual papers. Some people have gimmicks they use when giving talks that make them memorable (one friend of mine has a fondness for pink and makes slides that definitely reflect this. Personally, I often include hand drawn illustrations on mine) however, this can't be overdone or it will detract from your science. Put some thought into your presentation. Although many people do it, I don't recommend working on your slides at the conference at the last minute, but more on this in a second. At larger conferences, it may be harder to secure a talk slot, especially if you are earlier in your PhD. Writing compelling talk abstracts for the selection process is a skill that can be worked on with your supervisor. If you are instead offered a poster slot, there are a few different schools of thought, but I do believe posters are largely a huge waste of time and money. You're better of printing a few A4 handouts that summarize your work and pinning them to the poster board. Focus your time on your 1 minute poster talk/sparkler slot.

4. ... and actually practice it before the last minute

The number one way to test everyone's patience is to have a talk that runs over the allotted time. Because of this, you absolutely must practice your talk, as you intend to give it. This means standing up, talking out loud, preferably in front of a friendly audience who can give constructive feedback. Not sitting behind your computer reading through your slides. While some people think scripts are a terrible idea, I'm a big believer that a well-deployed script is vital. A well-written and rehearsed script should sound as easy as casual conversation, and you should know it so well that, if you are caught by a question in the middle of the talk, you will not be thrown off. Drama/improvisation classes, or specifically classes that teach how to act from a script can be very helpful here (I grew up performing in various theater productions). A good script does not sound wooden, and you can be sure you are delivering all the information you intend. And it can be consistently replicated, which helps with the timing thing. If there's one thing you take away from this, remember that the cardinal sin of any talk is a talk that runs over time.

5. Use your supervisor's network to build your own

Your supervisor has been to many conferences, and possibly worked in a number of different institutions. Consequently, they will have a large network of both collaborators and friends. Discuss with your supervisor whether they are happy to introduce you to these people at a conference if you attending together, or whether they can facilitate an introduction via email before hand if not. Virtually every supervisor I know of is more than happy to help their students network. You're likely to stay in roughly the same field as your supervisor if you go on to work in academia, and you will probably find their network overlapping with your own. This doesn't mean you shouldn't go out and form independent connections with other academics, but it can give you a boost to start with. Thanks to my supervisors, I've managed to build a network of friends and collaborators in academia across the globe.

6. Don't just sit in the corner with the other students

As tempting as it is, and as intimidating as it can seem, you need to go out and talk to people other than your immediate peers. Meeting more senior people at the conference can lead to some pretty amazing opportunities: these are the people with the money and resources to support your work and career going forward. While it's tempting to gravitate toward the student table, and to stay within your comfortable friend group, I do advise going to sit in part of the auditorium with different groups of people, as well as mixing with everyone during breaks, lunches and especially at the conference dinner. I joined the Dark Energy Survey because there weren't enough seats for me to sit with students at my first ever conference dinner, and I ended up sitting beside one of my now-supervisors.

7. But don't forget to talk to other students

Despite the points above, I don't recommend ignoring other students! Other students are likely to be your peers and you will probably be working with some of them for the next 40 years. Students can give you important insights into what it's like to work at other institutions you may be considering for future employment, or what it's like working for certain academics. They also have more of a perspective of the stresses that students currently experience. Networking with other students enables you to build the working relationships that will carry you through your career and give you alternative perspectives. Don't be afraid of talking about future scientific collaborations with other students - I'm currently working together with someone I met when they were a PhD student on a new project mostly independent of our supervisors.

8. Go to the conference dinner

It's probably expensive, but this is a way to get to know more about your colleagues in a slightly more informal setting. I always say you should only work with people you can sit down and have a cup of coffee with without talking about science. The same goes for being able to sit down for dinner. It's a way to get to know people better, not to mention next time you meet up at a conference, someone will probably start to reminisce with a "remember at the last conference dinner we were at..." - the importance of shared experience is understated in building collaborations

9. Get Twitter

"Social media is terrible, it's a distraction" - maybe, but Twitter is also a way of networking. I've lost count of the number of people I have met in person after following them on Twitter, which then becomes a nice talking point. It's also a way of getting your name out if you haven't yet published. When it comes to Twitter, I recommend creating an account where you share predominantly professional information, while still allowing some personal flair to show through (you can look at my Twitter account here). I tend to share interesting science information in general, as well as about my research and what it's like to work in Australia. I avoid sharing and making strong political statements (although there's nothing wrong with this, plenty of successful scientists do). Use replies to others judiciously, and if you use Twitter to send direct messages, I never say anything in a direct message that I would not post publicly (treat it like a less confidential email). There are plenty of articles out there with guides to tweeting as an academic. Used well, it can enhance your profile significantly (which has been my experience) but used badly or, worse, inappropriately, can potentially do damage.

10. Follow up your new connections

So the conference is over, what next? I think it's relatively common, firstly, to have a period of feeling somewhat flat or deflated for a week or so after a conference. You go from having exciting science input constantly, to being back alone in your office faced with the mountain of your PhD. One thing to do to combat this is to begin actively following up your new connections. Follow and tweet to people on Twitter, and send emails to anyone you would like to further collaborate with - something as simple as "Nice to meet you at <conference>, here is the paper I mentioned". Following up your connections relatively soon after the conference is the best way to keep momentum in a new project.

Cassini: The end of an era

Or alternatively: How a gamma-ray astronomer ended up being invited to watch a space probe crash into a planet

I often think that high energy astrophysics (the gamma ray kind, not the kind of astronomy done after overindulging in coffee) suffers from being trapped within the confines of the ivory tower more than other areas of astronomy. The main reason for this, as I see it - or rather as I don't see it - is because we humans have been blessed to have evolved without the ability to see gamma rays and x-rays. And there's a lot more romance at looking up at a starry night sky with your own eyeballs than hacking away at data with some heinously complicated deconvolution algorithm anyway.

 

There's also the scale problem. There are numbers the human brain can deal with, and then there's numbers that are just so unfathomably ridiculously large or small that a warning light comes on and the information you're trying to convey bypasses the brain entirely. I mean, what sounds more impressive: 1.2 billion or 10^43 (a one followed by 44 zeros)? 0.000001 or 10^-27 (a 1 preceeded by 26 zeros after the decimal point)?

 

The problem with gamma ray astronomy is it is the science of the unseeable, resulting from unfathomably tiny things doing things after unfathomably long times at unfathomable distances away from Earth. To make this understandable, a lot of time goes in to translating ridiculous numbers into something that humans can relate to. For example, to match the rate of production of antimatter positrons in the Galaxy, you'd need one solar mass of bananas to produce positrons every second through the decay of radioactive potassium, which results in some fairly weird mental images but at least it's vaguely understandable

Bananas are sadly not the source of most Galactic antimatter, as proven by a paper published earlier this year by my research group.

Bananas are sadly not the source of most Galactic antimatter, as proven by a paper published earlier this year by my research group.

Something wonderful about writing about the exploration of the solar system is that it's so intuitive. Nothing seems to capture people's imagination (mine included) than the existence of worlds beyond our own, and there's something incredibly tangible about the first voyages of discovery we make into our cosmological back yard. And much of this is thanks to the incredible work of the scientists behind the Voyager missions, and over the past 20 or so years, the Cassini mission to Saturn.

 

The reason Saturn usually tops the lists of peoples favorite planets is mostly thanks to the beautiful imagery Cassini has brought us over the past 20 years as it has studied the giant gas planet and its many unique moons. Many of the images of the planet, obtained by the Cassini probe 1.3 billion kilometers away in orbit around Saturn, released by NASA are almost indistinguishable from artists impressions.

An image of Saturn and its rings, obtained by the Cassini space probe. NASA/JPL

An image of Saturn and its rings, obtained by the Cassini space probe. NASA/JPL

This week, Cassini will end it's 20 year mission, crashing into the atmosphere of Saturn at 10:15pm Australian Eastern Standard Time. The probe has been slowly deorbiting over the past few months, diving between the planet's rings. The rationale behind disposing of the spacecraft by crashing it into the gas giant planet is simple: to protect the delicate environments of Saturn's moons - which could possibly harbour life -  from any human made debris.

 

I've been very fortunate to be chosen to be amongst scientists and journalists who will report live on the final hours of the Cassini mission from the Deep Space Communications Complex at Tidbinbilla, just outside of Canberra. It's exciting to be able to talk about science without resorting to ridiculous banana analogies, and to talk about something that inspired me to pursue a career in astronomy. Stay tuned for more Saturn related blogs this week, and don't forget to follow the final days of the Cassini mission via the #GrandFinale hashtag on Twitter.

I'm forever blowing bubbles

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What is the first word that pops into your head when I mention "space"? Stars? Planets? Galaxies? What's the first thing I think of when someone mentions "space"?

Bubbles.

Bubbles are possibly the most ubiquitous structures in the universe. We see them universally across all size scales - from the imperceptible "space-time foam" of quantum theory right to the massive supervoids - the unfathomably large caverns of nothingness that are surrounded by filaments in which galaxies live. At every stage of the universe's evolution, we can find bubbles. From the time of the earliest stars and galaxies, which produced strong ultra-violet radiation fields that would ionize the neutral hydrogen gas into great bubbles surrounding them, right up to the present day, where exploding stars carve out cavities into the interstellar medium. In fact, if time is "wibbly-wobbly" as the 10th Doctor says, space is almost certainly "bubbly-wubbly".

 

The nearby galaxy Centarus A (which also goes by the slightly less memorable moniker NGC5128) looks relatively innocuous in visible light, and the galaxy was first discovered by James Dunlop of Parramatta, Sydney, NSW, in 1847. For most of human history, we’ve only ever been capable of seeing our universe in optical light. However, the development of radar during the Second World War had some surprisingly dramatic implications for not only astronomy, but Australian astronomy in particular. Following the end of WWII, many of the devices that had previously been used to detect enemy ships in the Pacific were repurposed, and it was from Australia that many of the first astrophysical radio sources, then “radio stars”, were detected. One such object was Centarus A, one of the first localized extragalactic radio sources identified by the pioneering Australian radio astronomers John Bolton, Bruce Slee and Gordon Stanley in 1949.

 

Anyone with a fine pair of binoculars or a small telescope in the Southern Hemisphere can observe Centaurus A - it’s around 8 full moon diameters north of the globular cluster Omega Centauri (one of my favourite objects to target while I’m running a focussing sequence on the ANU 2.3m telescope). It has a bright central bulge, partially obscured by a prominent dark dust lane. What isn’t visible to the human eye, however, are the enormous radio lobes, or “bubbles” stretching away from the galaxy.

A multiwavelength view of Centaurus A. The bright colors show the varying intensity of radio emission from the powerful jet launched by the galaxy's active SMBH. From extragalactic.info

A multiwavelength view of Centaurus A. The bright colors show the varying intensity of radio emission from the powerful jet launched by the galaxy's active SMBH. From extragalactic.info

The radio bubbles stretch a remarkable 1.8 million light years from end to end. In comparison, it’s a mere 27,000 light years to the center of our galaxy, and four light years to the nearest star (Proxima Centauri - I promise that not all the interesting stuff in the universe happens in this one particular constellation). From Earth, the radio emission covers an angular area over 200 times greater than that of the full moon. But what is driving the radio emission so far from the galaxy itself?

 

The answer lurks at the very heart of Centaurus A. Astronomers understand that all galaxies contain supermassive black holes - SMBHs - in their very enters. Millions to billions of times more massive than the Sun, SMBHs have many ways of making their presence known. Like all black holes, which derive their name from the fact that nothing, not even light, can escape their gravitational pull after crossing the event horizon, the SMBH at the center of Centaurus A cannot be seen directly. However, dust and gas close to the event horizon of the SMBH creates an accretion disk - a donut of material that is accelerated in the gravitational potential of the black hole, a bit like water around a bath plughole.

An artist's depiction of an active galactic nucleus. The orange accretion torus swirls around the unresolved SMBH at the center. Plasma jets (white) are launched into the intergalactic medium.

An artist's depiction of an active galactic nucleus. The orange accretion torus swirls around the unresolved SMBH at the center. Plasma jets (white) are launched into the intergalactic medium.

 

With a large amount of material being fed into the accretion disk, the SMBH can’t help but be a messy eater. Thanks to the angular momentum of the swirling material, the black hole burps out massive jets of plasma - accelerated electrons and protons - into the intergalactic medium. As this jet ploughs through intergalactic space, the plasma expands outwards like a rocket exhaust, and the electrons in the jet interact with any ambient magnetic field. As electrons spiral around magnetic field lines, they emit a kind of radiation called “synchrotron” radiation. Here on Earth, we can detect this radiation as radio waves. Of course, this jet can’t keep expanding forever. Eventually, it reaches a region where it no longer has sufficient power to continue it’s collimated tunneling through the intergalactic medium, and gradually, over millions of years, a bubble forms, visible in not only radio waves, but also in gamma rays produced by electrons interacting with the radiation field that pervades the entire universe - the afterglow of the big bang.

 

Not all galaxies have their bubbles blown by active SMBHs. Many galaxies are actively forming new stars. For every hundred or so solar type stars that form (the most common kind in the universe), one star with a mass of greater than eight times that of the sun is formed. Star formation is often concentrated into pockets where molecular gas has accumulated, and such regions can have incredibly high specific star formation rates, resulting in the formation of clusters of stars classified as "high mass" by astronomers. While a star like our sun will live for around 10 billion years, these massive stars may only last a few million years before they exhaust their nuclear fuel, ending their lives as a spectacular core-collapse supernova. Because many of these stars will have formed around the same time, there will be a brief period where several stars will explode in quick succession (quick to astronomers being around a million years).

M82 is a prototypical starburst galaxy. Dust and gas is launched out of the central 500 parsecs (1500 light years) of the galaxy by the explosions of numerous core-collapse supernovae. From Wikipedia. M82 was also the host of the Type Ia supernova S…

M82 is a prototypical starburst galaxy. Dust and gas is launched out of the central 500 parsecs (1500 light years) of the galaxy by the explosions of numerous core-collapse supernovae. From Wikipedia. M82 was also the host of the Type Ia supernova SN2014J, one of my favorite supernovae to argue over (see my previous blog post, a retrospective of IAUS322)

 

This "starburst" is capable of driving powerful winds out of galaxies. Because molecular material is frequently concentrated in galactic spiral arms, or galactic centers, all of the starburst activity in a galaxy can drive a bi-conical outflow from either the galactic disk or center. The result is not unlike that of the case of the galaxy with the active supermassive black hole - gigantic radio, gamma ray and X-ray emitting bubbles are spawned above or below the plane of the galaxy. The main difference being that it can take billions of years to blow up a bubble using the combined power of core collapse supernovae, compared to only a few million years to form a jet-powered bubble.


So what about our own Galaxy? Until very recently, it appeared that our Galaxy had never generated these bubble-like structures. However, observations made by the FERMI gamma-ray satellite revealed the so-called Fermi Bubbles in 2010, and radio structures associated with the gamma ray lobes were revealed in observations made at the Parkes radio telescope in 2012. These bubbles stretch above and below the Galactic plane with an extent of some 40,000 light years from the top of the Northern Bubble to the base of the Southern Bubble. If we could observe gamma rays with the naked eye here on Earth, they would cover almost the entire sky. But what created them?

The Fermi Bubbles revealed by the FERMI gamma ray satellite in 2010. The Bubbles stretch above and below the plane of the galaxy, with a total extent of 16 kiloparsecs (~40,000 ly) from North to South. From kavlifoundation.org

The Fermi Bubbles revealed by the FERMI gamma ray satellite in 2010. The Bubbles stretch above and below the plane of the galaxy, with a total extent of 16 kiloparsecs (~40,000 ly) from North to South. From kavlifoundation.org

 

The clues to the origin of the Fermi Bubbles lies in the gamma ray energy spectrum. Spiraling electrons produce radio waves, and the interaction of cosmic rays with the interstellar and intergalactic medium produces gamma rays. "Cosmic ray" is a collective term for the extremely high energy sub-atomic particles that bounce around in interstellar space. Cosmic rays come in two varieties: leptonic (composed of "light" particles like electrons and their antimatter counterpart, positrons) and hadronic (composed of "heavy" particles like protons, neutrons and nuclei). Leptonic cosmic rays produce gamma rays through the "Inverse Compton" process - leptons interact with the ambient radiation field photons (primarily due to cosmic microwave background radiation, the afterglow of the Big Bang, with an additional component from the starlight produced by the galaxy) and emit gamma ray photons, which can then be detected by a space based observer. On the other hand, hadrons first interact with one another in the "pp interaction", producing a type of secondary particle called a pion (a quark and anti-quark bound together). These pions then decay to produce gamma rays, which can once again be detected by space-based observers. The gamma rays from the Fermi Bubbles cannot penetrate Earth's atmosphere, so can only be detected in space.

 

The gamma rays produced by these two processes are not all emitted at a single energy, but rather at a range of energies. However, constraints on the gamma rays that are being emitted by the Fermi Bubbles, and the various models of the different physics behind the formation of the bubbles means that the jury is very much still deliberating on the origin of the bubbles. If the gamma ray emission is primarily due to leptonic emission, the bubbles are likely to have been formed by a jet from our galaxy's SMBH some 8-10 million years ago. However, one thing we do know is that today, our Galaxy's SMBH is mostly harmless, accreting far too little material to launch a jet (although whether our Galaxy once had an active core, or could do again, is entirely within the realm of possibility - the novel "The Inferno" by astrophysicist and anti-Big Bang campaigner Fred Hoyle deals with exactly the scenario of our Galactic Center "switching on". But don't worry, it probably won't happen within the next few million years as today we know there isn't enough material close to the Galactic Center to support a quasar any time in the near future).

 

Another compelling argument against the short-lived jet scenario is that the Fermi Bubbles, and their radio lobe counterparts appear to "lean over" to one side of the Galactic meridian. This is likely to be due to the Galaxy's motion through the Local Group toward the Andromeda galaxy. A jet-inflated bubble would be too young for this effect to be so apparent, while a slowly-inflated wind-blown bubble would experience this effect more markedly.

 

Of the models advocating the starbust-driven-wind model, proposed gamma ray emission models account primarily for the hadronic cosmic ray scenario. The center of the Milky Way galaxy is truly enigmatic: the central 600 light years are responsible for 10% of the total Galactic star formation rate, and a number of young star clusters inhabit the region. The presence of these massive stars and the high star formation rate, together with the large concetration of molecular gas in the region (the so-called Central Molecular Zone) is strong evidence that there has been continual starburst activity, capable of driving a wind with velocities in excess of 500 km/s, over the past few billion years. The shockwaves that result from core collapse supernovae in these regions would be capable of accelerating protons to incredibly high energies, and these hadronic cosmic rays would then be carried away with this wind.

 

The Fermi Bubbles are among the most enigmatic puzzles associated with our own Galaxy, and the work done by astronomers to better understand them is a remarkable example of cross-disciplinary research. The Bubbles have been observed at almost every wavelength, from radio waves, microwaves, optical and UV (through observation of background sources to constrain the kinematics of the outflow), x-rays and gamma rays. With better constraints on the properties of the bubbles obtained through observation, and advances in computational capabilities allowing the simulation of the Bubbles, the coming years should see the scientific community begin to close in on the origin of the bubbles: the artefact of our Galaxy's violent past, or billion-year old reservoirs cosmic rays from more benevolent starburst-driven winds.

 

Thanks to Prof. Ron Ekers (CSIRO) for his presentation on the life and times of John Bolton, to Adam Thomas for the delightful analogy of AGN as messy eaters, to Prof. Geraint Lewis for the book recommendation (The Inferno), to Prof. Christoph Pfrommer for the fascinating discussion of the role of cosmic rays in galactic outflows, to Dr. Roland Crocker for the phrase "billion-year old reservoirs cosmic rays" and for teaching me pretty much everything I know about the Fermi Bubbles,  and to my copy editor (pictured below)

Retrospective: IAU Symposium 322 - The Multi-messenger Astrophysics of the Galactic Centre

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Sun, sand and serious science: the prescription for a week in the tropical paradise of Far North Queensland as, for the first time ever, the IAU symposium on the Galactic Center visits Australian shores.

The weather even cooperated with the organisers, with an entire week of almost wall-to-wall rain keeping the 150 or so astronomers from all over the world focussed on a wide range of interesting talks as opposed to long walks on the beach.  


To pick some of my favorite talks to highlight is somewhat self-indulgent and selfish, given my relatively narrow field of interest. I’ll try to be as unbiased as possible (so, still quite biased!).

To kick off, Wednesday’s second session was home of an outstandingly good natured set of talks on positron astrophysics. Thomas Siegert, who has been responsible together with the SPI/INTEGRAL team at MPA Garching for most of the recent analysis of the 11 years of data on positron annihilation in the Galaxy, gave an excellent overview of the topic. The new analysis of the SPI data has revealed some surprising truths about the location of most annihilating antimatter in the Galaxy, in particular the fact that as much antimatter is being annihilated in the Galactic disk as the Galactic bulge. This is contrary to the results from the first 5-8 years of data, which showed a very faint disk component to the emission, half of which could be explained by the annihilation of positrons being produced from the long-lived radioisotope Aluminum-26. Now as it stands, barely 10% of Galactic positrons can originate from this isotope, synthesised by massive stars, and the origin of most bulge positrons remains unexplained. Siegert gives a convincing argument for multiple origins for Galactic positrons, an argument I’ve certainly disagreed with in the past. Also just in are his excellent results on detecting 511keV emission in dwarf satellite galaxies of the Milky Way, which almost certainly deserves a blog post of it’s own. Read the just-published A&A paper here.

I was perhaps a little star-struck by meeting Nidhal Guessoum, whose work on positron microphysics and transport I’ve been using to inform my own work on simulating positron transport, energy losses and annihilation. Guessoum’s talk focussed on the plausibility of a source close to Sgr A* being the source of Galactic bulge positrons: positrons produced by Sgr A* itself, or a source nearby, can be diffusively transported out of the Galactic nucleus by MHD turbulence. The preliminary results presented look exciting, and I’m looking forward to seeing the final results.

Moving away from positrons and back to my old stomping ground of the Nuclear Star Cluster, I feel the need to highlight two excellent talks. First by Marion Grould, who discussed how observations using the GRAVITY instrument on the ESO’s VLT of the star S2, which occupies an elliptical orbit with a period of ~15 years about the central supermassive black hole in our Galaxy, can be used as a test of General Relativity. The simulations seem to say yes, so it will be exciting if the precession of the star due to the warped spacetime around Sgr A* can indeed be detected with this instrument despite the Newtonian perturbations on the star due to unresolved members of the NSC.

The origin of the NSC was also up for debate in two talks that occupied the Friday morning session. Oleg Gnedin’s talk on the formation of the NSC had me almost wishing I had taken the offer of a PhD place at University of Queensland investigating just that. The theory talk by Gnedin was beautifully backed up by a talk by Tuan Do on the observational constraints on the NSC’s formation. Do described the incredibly detailed data now available on the massive stars that orbit the monster black hole in the Galactic Center, and the take home message seems to be “watch this space” as these data are added to and utilized to investigate whether the NSC formed in-situ, or from the disruption of a Galactic bulge globular cluster.

David Nataf took an informative step back from 5 days of focus on, largely, the central 200pc of the Galaxy with his comparative review of the Galactic Bulge stellar population. Highlighted was this lovely work by Melissa Ness and Dustin Lang on the X-shaped feature in the Galactic bulge revealed in beautiful detail in WISE data.

Another particular highlight was the afternoon dedicated to a detailed discussion of the Galactic GeV excess. An observed excess of gamma rays at ~2GeV, a signal observed by the Fermi telescope that is sometimes referred to as the “Hooper Bump” has had two posited explanations: annihilation of a ~10GeV dark matter particle, or an unresolved population of millisecond pulsars. Convincing arguments were presented from both sides, from Richard Bartels, Dan Hooper and Chris Gordon. Francesca Calore presented an updated analysis of the gamma ray data while Doug Finkbeiner presented a thorough Bayesian look at the data.

I’ve somewhat skipped over some of the other topics covered. Remarkable things are being done in radio observations, probing accretion onto Sgr A*, the structure of the SMBH itself and the radio-emitting filaments of gas in the central regions of the Galaxy using incredibly high resolution studies. X-ray data from the likes of NuSTAR is also shedding new light on the Galactic Center region, although the untimely demise of ASTRO-H has disappointed many who were hoping that the new instrument would obtain more detailed observations of the 3.5keV line near the Galactic Center. The Event Horizon Telescope, which sees many of the world’s radio telescopes joined together as a colossal interferometer to probe in fine detail the structure of Sgr A*, was also discussed, along with how the new Cherenkov Telescope Array will provide an even sharper look at VHE cosmic rays being emitted from the Galactic Center region and perhaps shed light on the “Pevatron”.

The great strength of the conference, which brings together scientists with an interest in anything related to the central regions of our Galaxy, is that it opens up the opportunity for interdisciplinary collaboration. Theorists present their work alongside observers, and as the name of the conference suggests, every observation technique from radio through to gamma rays is well represented. The outcome of most of the well-attended panel discussions clear: We don’t really understand the central regions of our Galaxy (or most of our Galaxy, really) and in order to do so, we need to build a unified, self-consistent picture of how it works.

10 things I learned during my BSc(Hons) degree

1. Your project does not define your future research...

The great thing about a 1 year honors research project is the lack of commitment. Malcolm Gladwell claimed it would take 10,000 hours of practice for someone to become an expert at something (although this has been debunked as far as I can tell). If you take into account the amount of time lost to taking courses and completing assignments, you will spend 10-15 hours a week on your project. 2 x 12 week semesters makes ~360 hours spent on your research project. The fact is, that nobody is asking you to become an expert during your honors year. If anything, your thesis should be an exercise in learning the general skills you will later apply in a further research degree or in a job. It is far more important to choose a project which interests you and allows you to develop skills like computer programming and data analysis than a project which will result in publications.

2. ... But you may findPhD project through your research!

Your honors degree is a great opportunity to learn about all things related to your topic. In order to understand the context of your project, you will likely have to do a short literature review. This means learning how to read scientific papers (more on this in a second), interpret the results that are being presented and further explore anything that catches your interest. My current research is tangentially related to my honors thesis - searching for papers about the Galactic center lead to me learning more about gamma ray astronomy, and ultimately stumbling on the work of my now supervisor.

3. Attend journal clubs

If your university offers journal clubs, attend them. Even if you are the only student there. Even if you don't understand what the hell is going on for the first six months. Attend the journal club. You'll be surprised what kind of things you pick up via osmosis in these settings. As you get more confident, learning to present a paper you've read is an awesome learning exercise for many reasons. Firstly, it teaches you to critically evaluate the information presented in a scientific paper. Secondly, it gives you vital experience in presenting ideas to other scientists who may not be au fait with all the information you are presenting. Thirdly, it requires you to read scientific papers. If you want to do further research, this is a skill you must learn at some time. And finally, you will make connections with other students and staff who can assist you in ways you may not expect: as mentors, to bounce research ideas off, and to provide references when you eventually move on to a job or further study.

4. Pick a mentor

Your supervisor should be the first person you turn to for advice, but it is also important to have someone who is not directly involved in your research project to discuss work (and, in some cases, grievances) with. There is a lot of advice out there about choosing a mentor, who to look for and how to ask. You may be surprised who is willing to be your mentor - it is not necessary that they are in the same field of research, or have necessarily followed the same career trajectory you hope to follow.

5. Stop comparing yourself to other students...

And by the same token, stop competing. Unfortunately, this is not something I learned until far too late, being an extremely competitive person. In the end, by comparing your work, your research output or the complexity (or not) of your project to others, you will only hurt your own work and psyche.

6. ...And don't let other people compare you to others either!

Once again, something I learned all too late (I still struggle with both 5 and 6 here). There is definitely a comparison ethic in academia, and it is important not to buy into it. It is harmful in all too many ways. Find ways of diffusing situations where you see this happening.

7. Get all the public speaking experience you can

I taught an undergraduate lab class where the final assessment at the end of an experiment had a substantial oral component: Students were made to stand in front of a whiteboard and answer questions posed by the two demonstrators responsible for overseeing the experiment. At the beginning of semester, students would often cower beside the board, speak quietly and almost apologetically. One student I recall actually taking to one side after this short exam. His answers were excellent and mostly correct, but he looked at his feet, mumbled and answered in such a passive way. The main thing I remember telling him was to answer everything with confidence, even if he wasn't sure it was correct. It took the entire semester, but by the end he was giving animated responses and regularly getting 95+% for his exams. I have so much more to say on the subject of public speaking, but here I present one of advice: Practice at every opportunity you get. This is a skill which is vital!

8. Write constantly.

Writing, like public speaking, is one of the soft skills that students often realize is important far too late. Once you begin to practice writing regularly, it becomes easier. In fact, one of the easiest ways to start is to acquire a Twitter account, and join the academic community on Twitter. Writing less than 120 characters is a reasonably good place to start writing practice. In academia, brevity is mostly rewarded: the ability to succinctly and simply explain your research is important when one begins to write papers. A journal or blog is also a good start. It may not directly contribute to your thesis, but it does give you practice not only in writing, but in developing your own voice. There are individuals whose writing I can recognize from seeing a conference abstract. And the more you practice writing, the easier it will be when you come to write your thesis.

9. Start writing now.

I started writing my thesis around the mid-year mark. I was finished with the first draft a week or so early. A number of my classmates stayed at uni all night on the day before their thesis was due to complete them. Start writing as soon as you have material to write. If you have just started your honors year, I guarantee you have enough material to write an abstract and part of an introduction. It doesn't have to be perfect, as long as you write something down it can be edited. As an addendum: NEVER delete anything you have written. In LaTeX, it is possible to comment out text you no longer wish to use. In MS Word, move unwanted text to another document. But never, ever delete what you have written. You never know when it might come in handy.

10. Have fun

Of course, your honors year is important academically. However, you should not let the pursuit of good grades get in the way of having adequate downtime and enjoying yourself. It is important to work hard, but it is also important to enjoy your work. Ensure you plan times to spend with friends (not talking about work). Get some exercise, even if it's just a walk around the park at lunchtime. Make sure you laugh at least once a day (preferably more). It's easy to be passionate about your work in the future if you always make sure you are having fun while doing it, so start building the good habit now. And you have earned the right to be proud of yourself - you're working hard and I congratulate you for that!