Oh Canada

This week I visited just about every University in Canada. It was a trip! Some initial issues were encountered (did you know you need a visum? that you pay for online? Like Australia and Disneyland, it's better to order online well before going... I hadn't). So some stress getting to the plane. No bourbon brought along for my Canadian friends.

Monday

I forgot Queen's University isn't in Toronto. Google lady tells me with great authority that it is downtown and so I am late to my own talk. Swell. My host, Stephane Courteau is gracious and improvises a very nice visit. Beautiful place. Fun group and astronomers. I talked about overlapping galaxies. Stephane egged me on to publish the dang results already. The place comes highly recommended. Next time he organizes a conference, I should go. Back to Toronto I drive (2.5 hrs...)


Tuesday

York suffered a catastrophic electrical failure. I blame squirrels. The black ones that are everywhere. So there was some more improv and a giant generator truck and I managed to give a talk anyway.
Adam Muzzin was a solicitous and entertaining host. Wonderful visit. Interesting discussions (mostly with Adam, some reminiscing of Leiden times). My talk was about super-8s and M-dwarfs.


Wednesday

University of Toronto. The Dunlap institute. Clearly one of the flagship places of Canadian Astronomy. Renee Hloszek was my host and in between a clearly very hectic schedule she managed to get me where I needed to go and I got to talk about LADUMA.
I managed to chat to Brian Gaensler (score!) and I had a wonderful lunch. One of the other astronomers pointed out that Margaret Atwood was sitting right behind me. Sure. ok. NBD.
Then came the drive to LONDON (Ontario). Canada is built to a different scale people.
There I met up with Pauline Barmby and her charming family. She has a whole teenager now. Tried to learn something about managing that while at dinner (poutine! I have heard much about it).

sidebar: I had heard so much about poutine that it had been built up in my imagination. There is also a brown sauce Dutch people put on fries, the Thai Sateh sauce. Yep fries and spicy peanut sauce.
I may be biased but I like Dutch brown sauce much much better than poutine. I may never be able to enter Canada again after posting this.


Thursday

Talk at Western University. So many people to talk to. So much interesting science ideas to kick around. We chatted about the UGC 2885 project with Hubble. Plan to write All Teh Papers. I talked about Super-8s and M-dwarfs but considering how many people worked on nearby galaxies, I should have given a talk about overlapping galaxies. Ah well. Next time.
I chatted with Els Peeters, who I know from her Groningen Days. Her postdoc was working on something with PAHs (surprise! no surprise) and I may have a science idea there too. Hotel was a 1925 venerable building with lots of quirks. Like another power outage. Fun.
Chatted to several of the students. The astronomy and physics building is a lovely renovated old building with a cover courtyard. Very nice.


Friday

And on Friday, I drove to Waterloo, parked, walked 15 min to the Perimeter institute (why did they tell me to park here?) and then walk right back after I realized the talk was at the physics department. Part of the physics department had been burned down. And now they are getting a new building.
Maybe something to suggest to my physics colleagues. How inflammable are their experiment anyway?

Gave my talk about overlapping galaxies. Donna Strickland wasn't there but I think I spotted her at the Perimeter institute. Chatted to Brian McNamara who had been a postdoc in Groningen. And he informed me that Prof Strickland is now a full professor. All done with proper paperwork. Should have been a short discussion with the Nobel Prize in Physics and whatnot.

Then it was on to a quick maple syrup purchasing stop and Toronto airport, drop off car, navigate the check-in/customs/etc fly to Atlanta, sprint across Atlanta airport to make the connection in 20min, fly to Louisville and sleeeeeeep. Oh and I managed to write up three science cases for CASTOR.


This was a hectic week. Talk to someone, think up new stuff, talk to another person, try to be interesting and engaging, keep logistics in check, not forget power brick etc, move to the next topic.
It was fun and exhausting. Very happy to have visited and very happy to be home.

DotAstronony Thoughts

This year it finally happened! I was accepted into dot astronomy. The cool kids club. dot astronomy always seemed like the mysterious, creative, interesting gettogether where the thinking was free and the surroundings...well...cool.

Like all middle age people I crave to be a little cool? Plus I desperately need to update. Or so it felt. I cannot in good conscience teach people tools of the last generation (IRAF? C’mon). The face of astronomy is changing. Rapidly. And I - the perennial late-adopter- wanted to be part of it.

There were many topics and the organization is quite...free-flowing. I understand that is part of the appeal. To not be constrained by a strict format. But it also becomes a bit disorienting and tricky to contribute to. I wonder if i was the only one suffering from the “did i just miss that?” Feeling.

it started with day 0: introductions and stating goals. Everyone stand up (eek!) and say what you’re here for. There were several mentions of now finally being with “the cool kids”. And some pushback against that perception etc. But that is pretty on the mark. This was organized by a select group and this “brain trust” is a little social circle that is hard to follow and interact with. I totally get it. This is the one time these people get to see their friends and most important peers. But have a day -1 or +1 for the brain trust. The space (stsci) would have allowed a much larger crowd rather than the ~50 people present. Add to that there were lots of stsci people (that kept disappearing to their day job) this was a much smaller gathering than I thought it would be. I heard about the selection code. It is a small randomizer to ensure a mix of new and returning participants, early and late career. And worryingly, weighs your abstract using a text analysis. That seems like a great way to inadvertently select for native english speakers. I would like to test that worry.

The focus I had was on building class material, not tutorials. I noticed the focus of .astro is very much on research and outreach, and much less on education. And yet, training the next generation is absolutely key. Want to change astronomy and how it’s practiced? Teach it that way in thr classroom. Proper attention to contributions by women, start everyone off on Python 3 and Jupyter Notebooks from their first day. etc etc.

An exchange that stuck with me was about attaching Jupyter notebooks to publications (great idea) and how referees should referee this as well. The comment was that “everyone should just be able to read Python” which resonated with me because that’s the anglocentric argument that “everyone should just be able to write English”. Every non-native English speaker has stories about how referees scolded them for improper English (not their job) and people equating poor grammar to poor science. This could add a whole other layer of snobbery. No thank you.

But most of the time I really was there to learn new and interesting things. Jarita Holbrook gave an enlightning talk about how students of color perceive their interactions with Faculty. In both the US and South Africa. And having participated as a WMW (Well Meaning White) in both these places it was interesting to see her take on this. Another highlight was Lauren Chambers’ talk. Funny and informative. No need for me to talk. Go look at her thesis for more: http://www.stsci.edu/~lchambers/Chambers_ADifferentKindOfDarkEnergy.pdf

A big emotional moment was when there was a talk about the gender balance in science at the same time as the testinonies were before the senate. The overall feeling of things heading the wrong way at speed was pretty prevalent and maybe that colored my view of the week a bit too.

Oh and I needed to finish and submit ESO proposals and a SWIFT proposal. Didnt manage the SWIFT proposal. Ah well.

But I made some interesting new acquaintances. Some useful chats with people and I was encouraged to hear people liked my idea of a 100lvl coding, 500lvl astro class. That verbage was from Kelle Cruz. Her idea was to have a repository of different astronomy code repositories. That is the most tangible project for the future. I want to build a 100/200 level and 100/500 level classes.
And I ended up with a whole pile of ideas.

So I am calling my DotAstronomy a success. Didn’t get any cooler. Hardly talked to the Cool Kids[tm]. Not sure what to expect going in but I am calling this a win.

We all need a win.

Deliberate

A new semester and like a new year, I start with all the best intentions. After 18months in this gig I am feeling the stress from no upper limits to work, only vague instructions as to what is needed for tenure etc. but mostly: everything started to blur
together. Refereeing papers while taking small people to swimming lessons, sort of picking at my laptop while watching netflix etc.

And over the summer I read the book “rest” on how productive and creative people build in periods of deliberate rest into their schedule.

I did not latch on the rest part per se. A lot of the examples were people in the British aristocracy: they could take a break or a long walk or what have you, all the chores were being done by servants. Pwish!

But the deliberate part resonated. No more blurry lines between work and downtime. Delibrate downtime! No open laptop and watching “making it”! (Amy Poehler and Nick Offerman are National treasures!)

Deliberate breaks, deliberate parenting, deliberate work.

I mean the first week of the semester was still filled with starting issues but hey. I dod them deliberately. Ahem.

And one more deliberate thing: off my phone and one morning a week to sit down and write. Not at work of course. Far too many interruptions. Undisclosed location (coffee shop)

Student projects

my brain is pretty good at thinking up student projects. Losts of small projects and lots of instructive data-sets. But how does one keep them organized? This has been something I am struggling with. I have an Evernote notebook with ideas. But how to share effecricely with students? I need to think up a system. So kids can check them out and contact me.

Suggestions welcome.

The Dark Matter lacking Galaxy vol3, the Memes

After the Twitter/FB storm, the astro-ph reactionary papers, the memocalypse has arrived for the Dark Matter-less (oh sorry -lacking) galaxy.  

It's the same meme, based on the American Chopper series. And all of them mock the number of data-points, the statistics debate and the fact that someone is mumbling "MOND" every so often.

Fine. We're done now right? Time to get more data on more galaxies. 

Thanks to @jegpeek @astromeara and @MiaDoesAstro for the memes.

The Dark Matter Lacking Galaxy, vol 2

The dark Matter Lacking galaxy is certainly good for some more controversy.

various astronomers have weighed in, and now also on astro-ph:

Thanks to Justin Read for this quick summary:
https://twitter.com/ReadDark/status/984800166027776000

Three papers on the galaxy lacking DM:

Measured and found wanting: reconciling mass-estimates of ultra-diffuse galaxies


https://arxiv.org/abs/1804.04139  
With 10 tracers, there should be a factor ~10 error on the mass...

Current velocity data on dwarf galaxy NGC1052-DF2 do not constrain it to lack dark matter

https://arxiv.org/abs/1804.04136 

Where Nicholas Martin made good on his twitter thread (threat?) and generated a paper on the statistical treatment used in the Nature paper.

MOND and the dynamics of NGC1052-DF2

https://arxiv.org/abs/1804.04167 

Of course the MOND people had to weigh in, mainly with the point that this isn't the stake to the heart of this theory. Apparently you have to cut off its head too. Or something similar.

and this has prompted Pieter van Dokkum to post more information and material on his website:

https://www.pietervandokkum.com/ngc1052-df2

Especially, the actual table with redshifts and positions of the Globular clusters are posted here:

http://www.astro.yale.edu/dokkum/outgoing/ascii_table.txt

That does not sound like a big deal but to me it is. If you are being completely open in science (as we should be) then you make the reproduction of your approach and the test of other approaches as simple as possible. If I had one major gripe about the van Dokkum Nature paper, it was the lack of this table.

This allowed me to devise a rather simplistic homework assignment to calculate the mean redshift (systematic redshift) and the mean radius of the globular cluster distribution in kpc. One then takes the standard deviation of the distribution around the systematic velocity to obtain: 10.5 km/s and a radius r=3.6 kpc.

Yes that is just using Numpy's mean and std functions.

One can use this as an Jupyter notebook exercise for students to plot the data:


and the now infamous histogram:



Using our textbooks we get:

M = 7.5 {\sigma^2 r_h \over G}

and compare that to the stellar mass inferred from the Sersic fit and we find that this galaxy is lighter than the stars imply: something is definitely up.

So this is now a Dark Matter assignment in a new course I am building.

But that brings me to the current issue with this class of galaxies. We have way too few kinematic measurements of them, only done by one group and the implications are rather far-reaching. So, hopefully we'll see more data on these things soon. Because N=2 science in current circumstances is just embarrassing. 

Still not one of the most grumpy-old-man response I've seen: 

https://twitter.com/EricMamajek/status/984841037519708160

 #MamajekYourselfBeforeYouWreckYourself...

GAIA DR2 is coming soon!

So the GAIA satellite has been quietly plugging away, as it was designed to do, getting the astrometric distances to a billion stars. I played some with DR1, which mostly needed Hipparchos as a first epoch to get distances. Nice but nothing quite as amazing as a billion stars.

I heard a talk by Adam Riess at the AAS this winter on how they got astrometric distances to the long-period Cepheids in the Milky Way with much finagling on Hubble.Yeah. no worries. Now you can simply get the astrometric distance to the Magellanic clouds. The main uncertainty in the cosmic distance scale then comes from the lack of overlap between Cepheid distances and Supernovae.

Go figure. Three steps and that is the distances throughout the entire known Universe! We've come a long way! (literally!).

So why is this important? Because we're seeing the first pebbles shift in what promises to be a bit of a landslide in cosmology. Maybe. It's early.

Sangeeta Malhora posted a picture of a talk reviewing the tension between the distance scale(s) (there are different methods) and the Cosmic Microwave Background. This is interesting. Cool slide too. Totallywant to steal it from  Reachel Beaton who is giving the talk here. The distance scale is getting a different Hubble constant than the CMB is... that's...weird.

But some of the uncertainty comes from the very first step. GAIA is set to squash that first step's uncertainty.

I also have a just completely crazy idea (that just might work) for GAIA data as well. And maybe some ideas for student projects as well.

Sooon....