Exciting things are happening in high-energy astrophysics! The 2020 Astro Decadal Survey (which came out in late 2021) specifically mentioned developing a medium-sized (“Probe-class”) X-ray or infrared telescope mission in the coming decade for launch in the 2030s, and those of us who work in the dynamic high-energy sky were already on it. I’ve been a member of the STROBE-X team since 2016 when I was a PhD student, and I’ve been a member of the steering committee since 2017! We made a promo video introducing the broader scientific community to STROBE-X for the High Energy Astrophysics Division meeting in March:
Did you know it takes decades to develop and launch a space telescope? Currently, the priorities for the STROBE-X team is to grow our community support, further developing our science case, and improve our technological readiness level. I don’t think there will be a formal call for Probe-class mission proposals for a few years or so, but when it comes, we’ll be ready! Meanwhile, you can follow us on Facebook and Twitter. #XraysAreTheBestRays
In a terrifying departure from my modus operandi, I will be presenting a piece of creative non-fiction at the REO Town Reading Series on Thursday April 22nd! I’ll be telling a story about the brightest little pulsar in our galaxy. Join Mary Fox, Stevie Pipis, Selena Gambrell Anderson, and me with host and curator Matt Rossi on FB live starting at 7:30pm EDT.
UPDATE: Here is the video link for you to watch at your leisure! Thank you to everyone who tuned in. Transcript of my piece:
I’m going to tell you a story about the brightest little pulsar in the Milky Way, named Swift J0243.6+6124, and don’t worry, you don’t have to remember that name, and I’ll tell you what a pulsar is. On October 3rd 2017 there was a very bright burst of light near the Perseus constellation. It wasn’t close enough to see by eye, but things that go ‘bump’ in the night tend to be interesting to astronomers, so we had telescopes at the ready. The Swift X-ray observatory was the telescope first to detect it, which is why ‘swift’ gets to be first part of its name. The telephone number in the rest of the name, and yes we actually call it a telephone number, is its location in galactic coordinates, which is like latitude and longitude for the night sky. For the next 150 days, taking us into the spring of 2018, we saw this shiny new source get unimaginably bright, then dim again. Not only were there X-rays, but gamma rays, visible light, and radio waves also shone from it during that time, in their own ways. In the night sky, when something transient shines brightly in X-rays, this light often comes from near the remnant of a dead star, like a black hole. But calling it a dead star doesn’t quite convey its character; calling it a zombie star is far more accurate. Like zombie people, this zombie star is eating living stars, and it’s still quite active and spinning around, and in general, like zombie people, one could argue that its time as a zombie is far more interesting than its time when it was alive. Many zombie stars have a little star friend that they grew up with. They orbit around each other as they’ve always done, but like we’ve seen too many times in the movies, the little star friend can’t bring itself to leave, which ultimately leads to its untimely demise. The zombie star feeds on its star friend, slowly draining the outer material from the star and forming a disk around itself, like it’s greedily filling its plate. This syphoned star stuff, waiting to be gobbled down by the zombie star, gets very hot, like 100 times hotter than the surface of the sun. It shines its heat light in X-rays, so when we detect these particular colors and shapes of X-rays from a point in the galaxy, we know that this whole zombie scenario is happening. Now let’s check in with the ‘unimaginably bright’ aspect of this source. First, I need to tell you what we imagined the limit was. As a zombie star is eating, if it eats more stuff, it shines more brightly. But as your intuition may have already told you, things shining light in space cannot be infinitely bright. There reaches a point where the radiation of the light shining out, pushes back and doesn’t allow more material to fall in. If there’s enough material, the system can even sustain this luminosity. In the 1920s, this luminosity limit was worked out in detail by Sir Arthur Stanley Eddington, a British astronomer, physicist, and mathematician. An important detail to keep in mind is that this luminosity limit depends on the mass, or weight, of the object doing the eating. When we as astronomers are observing X-ray light from these voracious black holes, we often don’t know how massive they are, so we just pretend that they’re all 10 times the mass of the Sun. In the sciences, when we’re trying to figure something out but don’t have all the information (which is how it goes in astronomy, more so than other fields), we simplify, make a plausible assumption, and move on. Some of the sources we see in the night sky are brighter than this luminosity limit for a black hole weighing 10 times the mass of the Sun, and we call them ultra-luminous. Also, if you’ve ever wondered what’s more than ‘ultra’, according to astronomers, it’s ‘hyper’. So, two things could be happening here: either it’s actually more massive than 10 times the Sun, so it’s shining normally for its actual mass, or there’s some funky, fancy stuff going on that is temporarily letting it be brighter than it should be. But! Here’s the twist. You didn’t know there’d be a twist, but there is. When we were observing the X-rays from J0243, we instantly noticed pulses in the brightness of the X-ray light, nearly perfectly precise like the ticking of a clock. Black holes can’t pulse. There is no mechanism to get a signal this precise from them. However, neutron stars do, and some of them are so good at pulsing that we call them pulsars. Neutron stars are another type of zombie star, left over when a medium-big star is massive enough to die in a supernova, but not massive enough to collapse into a black hole. A pulsar is a neutron star with two bright spots on the surface at the north and south magnetic pole, off-kilter with how it spins. It’s like if a neutron star were a light house, in that it’s always shining beams of light, but you only see it when they point in your direction. Pulsars are effectively cosmic clocks that are stunningly accurate out to many decimal places, and NASA is testing a technology to use them like reference points for interplanetary GPS. So, knowing that J0243 is a pulsar, only a fraction the mass we first assumed for the luminosity limit, it is very super ultra hyper bright. It sounds like it shouldn’t be possible, but nature begs to differ. What’s probably happening is that the pulsar’s magnetic fields, which are thousands of times stronger than anything we can create on Earth, are holding things in place like Spanx, so it can eat even more and radiate even more. I think there’s an analogy here about Spanx holding stuff in, letting the star shine extra bright, but I prefer a more body-positive ethos so I’m going to let that slip away. What does this mean? I’ve been studying X-rays from this source, and one really interesting thing about it has to do with its iron levels. Though gas in space tends to be mostly hydrogen, there are trace amounts of other chemicals like oxygen, silicon, magnesium, and iron. If the gas gets hot enough (spoiler: it does), the iron can light up and fluoresce like neon lights. This shows up in cool shapes that we can see with extremely fancy and expensive X-ray detectors on satellites in space. If we want to know where this gas with iron is, like geometrically in the system, we can’t just take a picture because the whole system (zombie star, star friend, plate of stuff it’s eating) are way too small and way too far away. Instead we need to figure it out from the physics, like a more boring, yet higher stakes, version of Clue. We know the weapon and the victim and the murderer, but not the room, and the room is important. The big weird wrench in the gears here is that the iron doesn’t know that it’s around a pulsar. It doesn’t see the pulsations. And like, How can you not know with such a stupidly bright pulsar, but anyways. The two possibilities are that it has a wall of stuff blocking its direct line-of-sight with the pulsar, or it has a cozy cocoon of dust and gas wrapped around it, diffusing the pulses into a strong, steady light. I don’t have an answer to this yet. Scientific research is trial and error and error, ad nauseam, and I am in the thick of it. A very helpful colleague suggested some calculations I can do, but I haven’t done that yet, and instead I wrote this.
Thank you Skype A Scientist for having me speak yesterday! As one of the finalists for the No Time Like The Presentation contest, I gave a 10-minute presentation on my research for a general audience. It was the first time in ages that I’ve given a talk with almost entirely new slides. I was so nervous and excited, and it was so fun! The talks were recorded and posted to YouTube (see embedded below). I spoke first, but you should stick around for all the talks. I loved learning about everyone’s research.
First order of business now is to make a sign reminding myself to SPEAK SLOWER and hang it just above my monitors…
Astronomy research makes for an interesting and challenging career. In my experience, it’s one of the more collaborative physical sciences, and it’s one of the most fascinating things I could possibly be doing with my time. I’m regularly asked for my advice by high school and college/university students on what they should do to become a professional astronomer, so I’m sharing it all here. Other professional astronomers like Prof. Katie Mack also have advice on their websites!
Take physics, math, and computer programming (if offered). It will be most helpful to you if you can take pre-calculus and calculus 1 in high school, and AP/IB/honors physics (if available). Statistics is also very useful, but unfortunately you may have to choose stats OR calc, and I would probably recommend calculus for now (but listen to your teacher’s advice, since they know you and your program best). Much of astronomy is actually done with writing scientific research software for data analysis or simulations, so having a programming background is SUPER useful!
You can also look into summer research opportunities at your local college or university. As a researcher, it is often difficult to hire a high school student on their own for research, so it’s best to go through established programs. Check online for summer research opportunities both in your area and (non-local) residential programs.
When looking at colleges/universities, keep in mind that not all programs are equally rigorous. Many times, astronomy is part of a physics (or sometimes physics & astronomy) department, so you will take lots of physics classes. Do undergrads take two semesters of upper-level Electricity & Magnetism? Two semesters of upper-level Quantum Mechanics? Can undergrads take graduate-level classes if they complete the pre-requisites? Both small liberal arts colleges and massive public research universities can have rigorous physics and astronomy programs, so ask questions! Also ask what research opportunities there are for undergrads on campus (in addition to summer research), and how many students go on to grad school (if you think that’s something you might want to do).
Keep up with your athletic and artistic pursuits. Hobbies are good for the soul.
Again, take physics, math, computer programming, and astronomy (if offered), and meet with your advisor to be sure you’re fulfilling the course requirements for your degree. Make study groups with your classmates, and ask questions at office hours with your prof and/or teaching assistant. College is when the training wheels start to come off and you transition to being a self-driven learner, so your coursework will transition from being formulaic plug-and-play to being multi-stage problems that help you synthesize different aspects of the course material.
Talk with your academic advisor about research opportunities, both during the semester and the summer. Different universities have policies about doing this for course credit vs. being an hourly employee, so ask questions, accept advice from your mentor(s), and do whatever is best for your personal situation. Building on a former student’s research project is great experience, and is true to how most research actually goes!
Applying to grad school
If you decide that you really like research and want to pursue graduate school, talk with your academic advisor (and research advisor, if they’re different people). Again, listen to their advice. Chat with grad students, postdocs, and profs who work in areas you’re interested in, and ask them what classes are most helpful for studying that field. Remember that grad school in the US and Canada (and post-MSc PhD programs elsewhere) is *paid* and tuition is either covered by grants or very inexpensive. You should not be taking out a loan to go to grad school in the sciences. Iterate with your advisor (and even a writing tutor) on grad school application materials, and give your letter writers ample time (like 4 weeks notice) for the letters of recommendation. You can also ask a letter writer to include specific pieces of information to explain any discrepancy in your transcript, like if you had health problems and that’s why your grades dropped one semester.
Policies vary based on country and school, but often times you’ll be invited to visit either as an interview stage or after you’ve been accepted to grad school. Take this opportunity to chat with professors you want to work with, grad students (to see how happy they are and how much they’d recommend the program), and get a feel for the location and whether or not you could realistically live there for 6ish years. If you’re part of an underrepresented demographic and you don’t see anyone else from that demographic at that school, ask questions of mentors and current grad students (there and elsewhere) to figure out whether there’s a notable systemic problem there, or there just don’t happen to be any students of that demographic there at that time.
You should know that there’s a mental health crisis among graduate students, and graduate school is HARD (both emotionally and mentally). Part of the difficulty is because you’ve chosen a particular path and that path is challenging (research is part exploration and part banging your head against a wall). You’re also in a life stage with a lot of existential angst and growing pains as you figure out what kind of adult you are and what kind of life you want. Advisor fit is one of the better predictors of mental wellbeing among graduate students, so pick someone who you mesh well with and who you think will support and inspire you. Your advisor makes or breaks your grad school experience — a great advisor will help you find a niche that plays to your strengths in whatever sub-field you find interesting (like high-energy astronomy, or exoplanets, or quantum information, or optics); a negligent advisor will amplify feelings of loneliness and isolation, which can cause you to dislike a research topic that you might otherwise think you love. It can be tricky to judge the quality of a working relationship based on short interactions, but chatting with grad students (both in their group and not) can help fill in the picture.
Some final thoughts
Above all, know that it is very normal to change your dreams, and change your major, and change your job. There are new and varied challenges to being an astronomer as you move along the path from undergrad to grad to postdoc (and presumably to professor). There is more than one way to be an astronomer, and the community as a whole needs people with varied talents and areas of expertise — not just research, but also outreach, teaching, policy, and advocacy. Building your own support network of peers and mentors (more senior grad students, postdocs, and profs) can help you find your own path to success!
I wrote a guest post in AstroBetter about doing my MSc in Canada at the University of Alberta. Going abroad for a MSc is quite an uncommon path for US-born students in STEM, but I’m really glad I did it. Read the whole post here.
Here are my instructions for how to get HEAsoft, the NASA High Energy Astrophysics Software, set up on a Mac with macOS Big Sur (v11.6). I learned most of this from HEAsoft’s own documentation (and a lot of trial and error over the years). I work in bash, so adapt as needed if you use c-shell or zsh. Disclaimer: I’m not a HEAsoft developer or maintainer, so follow this advice at your own risk. Actual HEAsoft maintainers should be your first point of contact if something goes wrong.
Make a full backup of your machine as-is.
Install these things:
Anaconda Xcode from the App Store Command Line Tools for Xcode by typing in a terminal window: xcode-select –install homebrew (or another package manager like MacPorts or Fink) XQuartz
Download the HEAsoft source tarball. The first bullet point, above Step 1 on that page, should have everything you need (and you probably don’t need the extra old XSPEC stuff). This download takes like 30 minutes! I then put it in the directory ~/opt/ and unzip the HEAsoft tarball in there (tar -xvzf). This is a different location than what I’ve previously done! It seems that the new macOS really hates letting the user install things as su.
As it’s downloading, navigate to your old HEADAS directory and rename it to, e.g., old-heasoft6.28. This way there won’t be weird crosstalk. You can also delete your previous old-heasoft and tarball if you still have it. If you’ve never ever installed HEAsoft on your computer, you can skip this part.
In the ~/.bash_profile file, be sure that /usr/bin and /usr/local/bin are at the beginning of your PATH environment variable.
Restart your computer. I don’t know how necessary this is, but it’s one of the few things that changed in the few days between the install not working and working.
To configure, make, and install (your HEAsoft version number might be different when you reference this blog post):
cd ~/opt/heasoft-6.29/BUILD_DIR/ ./configure make > build.log 2>&1 make install > install.log 2>&1
Note that I’m no longer passing the X11 include and library directories to the configure script, as I’ve had to do in previous installs. You should be able to open build.log and install.log as those things are going (from a different terminal window) to see their progress. You can also use tail build.log and tail install.log to view the last 10 lines of the files (though this won’t update, so this is more for occasional checks).
The make line with build.log takes a particularly long amount of time (like 20ish minutes). Since it’ll use a lot of memory and you’ll hear the fans going as it’s makeing, I don’t recommend playing videogames on your computer in the downtime.
Copy/paste into ~/.bashrc for general use (again, your HEAsoft version number and system architecture might be different. If you ls in the HEAsoft directory you’ll see what to put for the system architecture thing):
export HEADAS=/Users/YourUserName/opt/heasoft-6.29/x86_64-apple-darwin19.6.0 alias heainit=”. $HEADAS/headas-init.sh”
To start up XSPEC, in a bash terminal session type
and it should start up an XSPEC environment! Happy analysis!
I’m at the stage of my PhD where I’m finishing research for and writing up my last two chapters (and then putting together a broad intro and conclusion for everything), and writing two fellowship applications, and sometimes I have trouble focusing on what I’m working on. I asked my wonderful friends on Twitter and Facebook who’ve written theses and papers for their advice, and it’s all so good! So I’m sharing it with you! It has been lightly edited for flow.
(And yes, I know I’ve written two theses and two first-author papers before. Apparently I’ve blocked it out.)
Make a plan
“Maybe make an outline with just the section, subsections, etc first, and then fill in. It’s actually a good idea to do that as soon as you are pretty sure the results will turn into a paper.” – Tom Maccarone via Facebook
“Lay out a timetable with achievable goals for each day/week and stick to it. Also vary what you’re doing, one paper one week another the next.” – Lucy Heil via Facebook
“Make an outline to keep it organized and keep you on track. I also don’t write in order. I’ll start at the end and jump around based on how I’m feeling. What also works for me is a change of setting or writing in a notebook instead of staring at a computer screen.” – Desi Paynter-Plivac via Facebook
“When I have a big deadline, I find it helpful to really use a daily planner and write in everything, especially those things that always seem to distract me (social media, email, housework, etc). I give myself a set time of the day to check email or Facebook. When I’m tempted to go there, I remind myself, ‘no, you get to check Facebook at 4, not now.’ I actually need to do this more.” – Rachel Frey via Facebook
“For myself, I know I can’t get myself to write papers that don’t tell (compelling!) stories. So I’m very selective about what I take on.” – Richard Scalzo via Twitter
Break it into bite-sized chunks
“Don’t make the thesis a goal. Make a small piece the goal, and then move on to the next goal.” – Tom Maccarone via Facebook
“DO NOT sit down with ‘write the whole thing’ in your head. Focus on a small part, e.g. spectral calibration with Blobbo spectrograph.” – Matt Kenworthy via Twitter
“Break it down to many small components (more than 10) and establish rewards for each (a walk, baking, TV)… Good luck!” – Anne Pasek via Twitter
“Break it down into small chunks and have lots of treats to keep you going. Stu usually had a chocolate bar in the car for me when he picked me up from the office. Also, it’s hard but take a small break either when you can or get someone to make you take one. So don’t eat at the desk, grab lunch or a coffee elsewhere. Gives you a chance to come back fresh. Evens if it’s only 5 mins, it can make a huge difference. I know it’s hard to take them but it’s better for you in the long run.” – Jeanette Gladstone via Facebook
Just start writing
“Try a free write. For me, this works best with pen and paper in longhand. It works like this, just set a goal. It can be time (e.g. 10 minutes) or a number of pages (e.g. 3, longhand) and write whatever comes to mind. Write all the distracting thoughts. Write your dream from last night. Write how much you hate writing. Write what you wish you could write in your thesis. I find this gets all those distracting thoughts out of my head. Most of that I write in my free writes is crap. But occasionally something good comes up. And when that does, I just copy to my computer. But I don’t expect anything there to be good.” – Rachel Frey via Facebook
“I like starting with writing the results section, or even just the captions of my figures, because the results are the exciting bits. 🙂 Basically, just start anywhere that feels manageable to you, and make sure you give yourself plenty of rewards. Writing papers is hard!” – Daniela Huppenkothen via Twitter
“Try distraction free writer, say ommwriter or google for free one. Pomodoro it. 29 minute timer, shut off all other windows. Just write. Then get out of your chair and stare outside.” – Matt Kenworthy via Twitter
“Often writing gets me in the flow, and at least it avoids spending hours/days staring at a screen. I’ve always found ‘just write’ to be solid advice. Forcing yourself to write something, even if it’s not perfect / needs to be rewritten.” – Vincent van Eylen via Twitter
“Don’t write it in order, write the bit you have the idea for. Also don’t force yourself to write if you have no inspiration, sort figures etc. until you do and then write whilst you have the thought. Don’t try to edit as you go along, get all ideas down then go back and reorganise. That’s what worked for me.” – Charlie Feldman via Facebook
“I forced myself in a harsh way to sit every day and write. No calculations, no data, no anything else, but writing only, and I forces myself to write at least 2 news pages every damn single day even if I rewrote previous pages, the manuscript has to increase by 2 text pages no matter what (I do remember how some days were very long…, that period took about 3 months) and then another 3 months went into polishing it.” – Natasha Ivanova via Facebook
“I managed by hitting up a coffee shop everyday for 3 hours. In those three hours, at least three paragraphs must be written. Why only three as my limit? Realistic expectations. Better off with few solid paragraphs than pages of BS that have to be rewritten!” – Hoang Pham via Facebook
Take frequent breaks
“On big projects, I set a timer for 20 minutes, write as many words as I can in 20 minutes, & edit it later. Easier to edit than from scratch.” – Diana Crow via Twitter
“Something like the Be Focused mac app where you only focus on a specific task during each, say, 25 minute slot and don’t do anything else. Then take a break when the time is up. This helps me so much when I’m really struggling to focus.” – Emily Petroff via Facebook
“I don’t use it myself, but I know a lot of people who use the Pomodoro timer. It makes you work for 25 minute blocks of time and then take a break. Good to use if you feel like you don’t know where to start or the project feels too big.” – Emma Gonzalez-Lesser via Facebook
“I use timers all the time. For everything. Any task that seems overwhelming isn’t so bad if you tell yourself, ‘I’m only going to work for 10/15/25 minutes, then take a break and do something else.'” – Rachel Frey via Facebook
Save the rest for when you’re feeling out of it
“When you can’t write, make figures and tables. Better yet, always make them first.” – Maria Womack via Twitter
“You can always put together what you have. Plots, method..previous work. Even outlook. Just get writing. Don’t expect to be super-motivated before writing. It’s ok when it feels like a drag. Start anyway. For me motivation comes with writing.” – Ludmila Carone via Twitter
“Inserting the references, figure/section/equation links, etc… is another such thing. I prefer just to have placeholders when writing to not disturb the flow. Then do the ‘dumb’ things when I’m tired.” – Remco de Kok via Twitter
Mix it up!
“Switch locations where you’re doing the writing, for me it’s easy to burn out a place and get into an unproductive rut. When I was writing my thesis I’d rotate between the office, the Library, home, and a coffee shop as I burned each place out. If you have multiple papers on the go, procrastinate on one, by working on the other.” – David Tsang via Facebook
“Have a token or clothing item that you only wear while you’re working on your thesis. I had a thesis scarf that when the scarf went on it was time to work. Also then other people can see you’re wearing your thesis scarf and they leave you alone (a friend had a thesis tiara which was arguably better).” – Emily Petroff via Facebook
“Steve Reich and standing desks. Music for 18 Musicians and Electric Counterpoint – makes you feel like everything you are writing will change the world.” – Brian Barth via Facebook
“Okay this may sound crazy but I was once in a class where we did yoga for focus and it was really helpful. You do like 2-3 minutes of sun salutations while focusing on a small goal, then immediately sit down and do it. You slow your breathing and heart rate down and clear your mind and then it becomes a lot easier to focus. Repeat as needed.” – Anna Lenti via Facebook
Take care of yourself
“Be kind to yourself and know that some days you won’t write very much and that’s ok.” – Benjamin Pope via Twitter
“I’ve found that having a ‘thesis buddy’ really helps me. She and I chat about how much progress we’ve made (a positive conversation) and sometimes meet up and write together in the library to stay motivated. I’ve also found that working somewhere with natural light helps me stay focused.” – Mackenzie Jones via Facebook
“Making your work environment as pleasant as possible is important. Whatever makes you feel good…a nice flower on your desk, scented candles, pictures of your loved ones, a hot cup of coffee… Whatever it is, but put it on your desk and make your work place your favorite place to go to. Also when I lacked inspiration, I would just take a break, walk through the woods and get back to work later. If you’re into essential oils….lemon and peppermint help with focus and mood! You can do it!!!” – Silvie Solana via Facebook
Writing this up as a blog post was one of my treats to myself for fixing some giant tables and making a big detailed combo-plot! As you can see in the top photo, I took Silvie’s advice and turned the spare room into a writing corner — so far it’s working! Good luck hugs to everyone else who’s writing up 💖💖
The paper from my MSc research has been accepted for publication in ApJ!!!!!
We simulated pulse profiles from thermonuclear X-ray bursts on the surfaces of accreting neutron stars, and fitted them with an evolutionary optimization algorithm to determine how well we could constrain the masses and radii of the neutron stars! The ADS entry for it is here. We’ll update the arXiv version once the proofs are finished!
I’m thrilled to say that my first paper has been accepted for publication in MNRAS!! 2.5 years into my PhD and I finally have something to show for it 😁 Here’s the ADS link, which has both the arXiv and MNRAS versions.