Aritra Ghosh I অরিত্র ঘোষ

Lights, camera, action!

The world's largest digital camera has been installed at NSF–DOE Rubin Observatory! 🤩

The LSST Camera was the final major component of the observatory. With it in place, Rubin officially enters its final phase of testing!🔭

🔗: rubinobservatory.org/news/lsst-camera-installed

🔭 Has someone already made an Astro X ML/AI starter pack?

Figured I would get in on this whole starter pack thing and list (in whatever order bsky chooses) scientists working on studying galaxies (broadly defined, including galaxy formation/evolution + near-field cosmology). If I missed you and you'd like to be added, let me know!

🧪🔭

go.bsky.app/5ZZtqDy

Are you on the Postdoc market and excited about early science with @vrubinobs.bsky.social, especially time domain, solar system, near field cosmology, or SETI? Well check out the @dirac-institute.bsky.social fellowship position that just got posted!
apply.interfolio.com/158267

OMG look how glorious 🤯

#NancyGraceRoman #SpaceTelescope #astronomy

A calendar showing the Picture an Astronomer events: January 30 - Kick-off event February 3 - Dara Norman Public Lecture February 7 - Katie Mack Public Lecture February 19 - Jocelyn Bell Burnell Public Lecture February 25 - Anna Frebel Public Lecture March 4 - 6 - Symposium

Perhaps more timely now than ever:

We are hosting a scientific symposium (among other events -- see pic) at UChicago, focused on promoting and retaining women in astrophysics. Symposium registration (link in next tweet) is open through Jan. 30 and we offer hybrid attendance.

🔭👩‍🔬🧪

Grateful to see our recent work covered by space.com !

The article is wonderfully done @monisharavis.bsky.social ! It captures everything so well while being an interesting and easy read! :)

#🔭 #astronomy

A huge shoutout to my co-authors:- Meg Urry, Meredith Powell, Rhythm Shimakawa, Frank vdBosch, Daisuke Nagai, Kaustav Mitra, and Andy Connolly!

(11/n)

My own blog post on this, including links to our public code, models, and public catalogs:-

https://ghosharitra.com/hsc_rad_den.html

(10/n)

Here’s what millions of galaxies say about their size, growth A Yale supercomputer is helping astronomers resolve a longstanding question about the sizes of galaxies and the environment in which they live.

Jim Shelton describes how this work was powered by a public catalog of structural parameters for 8 million HSC galaxies.

https://news.yale.edu/2024/08/14/heres-what-millions-galaxies-say-about-their-size-growth

https://iopscience.iop.org/article/10.3847/1538-4357/acd546

(9/n)

A wonderful write-up on this from James Urton at UW News summarizing how our work helps to settle some long-standing questions while raising new ones:-

https://www.washington.edu/news/2024/08/14/galaxy-size/

(8/n)

If I have got you intrigued, take a look at the paper and the press releases!

ApJ Link: https://doi.org/10.3847/1538-4357/ad596f

arXiv Link: https://arxiv.org/abs/2408.07128
(7/n)

... should depend on environmental density (at a fixed stellar mass and morphology). Although some previous theoretical works can be selectively invoked to explain some of the correlations, our work demonstrates the need for more comprehensive theoretical investigations!

(6/n)

Due to its dynamic nature, galaxy structure is a powerful probe of both dark matter halos and the baryonic processes inside them.

There is no straightforward explanation as to why the sizes of galaxies across different morphological types and star-formation states ...

(5/n)

An alternative way to answer the same question is to investigate the size-mass relationship for galaxies in different environments.

We did that and found that even at higher redshifts, the size-environment correlation exists beyond a certain stellar mass threshold!

(4/n)

How did we reach this conclusion?

We correlated the deviation in effective radius from the average size against
density excess measured using a top hat of 10 co-moving Mpc.

We find the correlation to be strongest at lower redshifts and weaken in the last two z-slices.

(3/n)

This comprehensive study is an important step in resolving decades of contradictory results on this topic (see table below). It also sheds new light on how the structure of galaxies is connected with their dark matter halos; as well as their merger history.

(2/n)

🎉 🎉 Paper + Press Release Day 🎉 🎉

Using 3 million Hyper Suprime-Cam galaxies, we demonstrate with >5σ confidence that galaxies in denser environments are up to 25% larger than their counterparts with similar mass and morphology in less dense regions of the Universe.

(1/n) 🔭, #astro

@bot.astronomy.blue signup

Eclipse: You shall wait for years, make careful plans, drive hundreds of miles for five miraculous minutes.

Aurora: U up?

What an amazing night in Seattle!

Looking for a #astronomy postdoc this cycle? Excited about Rubin/LSST, big data/AI, building tools, finding the weird/wild/wonderful things in surveys? Check out the DiRAC Fellowship!
jobregister.aas.org/ad/9be8c8f3