Vivian U
@justtheletteru.bsky.social
Associate Scientist at Caltech/IPAC studying black holes and galaxy mergers with a nerdy sense of humor. Roman Proposal Lead. < 15 minutes of fame from PBS NOVA showcasing JWST science. TEDxMB 2024 speaker. Views are my own.
🌐 https://vivian-u.github.io/
🌐 https://vivian-u.github.io/
This paper presents a major update to the SIDES simulation framework, successfully modeling the large population of dust-obscured galaxies and AGN discovered by JWST/MIRI. We reproduce observed source counts and z distributions. 2/
September 22, 2025 at 6:01 PM
This paper presents a major update to the SIDES simulation framework, successfully modeling the large population of dust-obscured galaxies and AGN discovered by JWST/MIRI. We reproduce observed source counts and z distributions. 2/
Paper day 🎉🔭 Congrats to my student Raymond Remigio on acceptance of his 1st first-author paper! We mapped [O III] gas in nearby Sy 1s with @keckobservatory.bsky.social: gas kinematics align w/ stars at large scales, but many show twists/outflows near nuclei + large NLRs arxiv.org/abs/2508.14304
![NLR size vs [OIII] luminosity plot](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:sxsg5dpz6fz3gveh462lxrn7/bafkreiftv3fwcqzy5zeqqkb4xu2hy3pelaxdzfqdnll76h5h5yhje4h33a@jpeg)
August 21, 2025 at 2:10 AM
Paper day 🎉🔭 Congrats to my student Raymond Remigio on acceptance of his 1st first-author paper! We mapped [O III] gas in nearby Sy 1s with @keckobservatory.bsky.social: gas kinematics align w/ stars at large scales, but many show twists/outflows near nuclei + large NLRs arxiv.org/abs/2508.14304
Safe travels @marinabianchin.bsky.social, all the best with everything. Thanks for the past 3 years, you’ll be missed!
August 16, 2025 at 2:04 AM
Safe travels @marinabianchin.bsky.social, all the best with everything. Thanks for the past 3 years, you’ll be missed!
Missing JustinK & Yiqing, but this may be the last time our group gathers for lunch before Hajar leaves for PhD, @marinabianchin.bsky.social leaves for next postdoc, and JustinP leaves Cal-bridge summer program. With JustinK's departure in a month, this is one of those end-of-an-era moments for me 🥺
August 8, 2025 at 8:53 PM
Missing JustinK & Yiqing, but this may be the last time our group gathers for lunch before Hajar leaves for PhD, @marinabianchin.bsky.social leaves for next postdoc, and JustinP leaves Cal-bridge summer program. With JustinK's departure in a month, this is one of those end-of-an-era moments for me 🥺
There. I've now talked about IMBHs. (Photo courtesy of Chris Packam)
July 31, 2025 at 3:33 AM
There. I've now talked about IMBHs. (Photo courtesy of Chris Packam)
Not one but TWO papers from my group are published on ApJ within this past week! 🎉🎉 Tianmu Gao led the work on compiling nuclear SEDs of (U)LIRGs; Justin Kader studied cluster winds as engines of feedback in starburst galaxy 🔭
iopscience.iop.org/article/10.3...
iopscience.iop.org/article/10.3...
iopscience.iop.org/article/10.3...
iopscience.iop.org/article/10.3...
July 30, 2025 at 2:31 AM
Not one but TWO papers from my group are published on ApJ within this past week! 🎉🎉 Tianmu Gao led the work on compiling nuclear SEDs of (U)LIRGs; Justin Kader studied cluster winds as engines of feedback in starburst galaxy 🔭
iopscience.iop.org/article/10.3...
iopscience.iop.org/article/10.3...
iopscience.iop.org/article/10.3...
iopscience.iop.org/article/10.3...
Happy to share that I've been selected to join the leadership team of the new Habitable Worlds Observatory Science Interest Group, representing the Cosmic Origins community in particular. I look forward to working with my awesome co-chairs on furthering this inspiring mission! #HWO25
July 28, 2025 at 6:12 PM
Happy to share that I've been selected to join the leadership team of the new Habitable Worlds Observatory Science Interest Group, representing the Cosmic Origins community in particular. I look forward to working with my awesome co-chairs on furthering this inspiring mission! #HWO25
Back in my element - observing! I'm on @keckobservatory.bsky.social tonight with @marinabianchin.bsky.social for an OSIRIS run. This time I'm in the IfA remote obs room, which I had really only used for UH 2.2m observing as a 1st and 2nd year grad. Fingers crossed for a smooth sailing night!🤞🏻🔭
July 12, 2025 at 12:29 PM
Back in my element - observing! I'm on @keckobservatory.bsky.social tonight with @marinabianchin.bsky.social for an OSIRIS run. This time I'm in the IfA remote obs room, which I had really only used for UH 2.2m observing as a 1st and 2nd year grad. Fingers crossed for a smooth sailing night!🤞🏻🔭
I was among the fortunate fellows selected for the 2009 cohort. To me, JPFP represented more than just a nice paycheck that started me off the track of research independence. Instead, it also provided a supportive community and network where I met many other wonderful JPFP fellows... 4/
July 2, 2025 at 8:40 PM
I was among the fortunate fellows selected for the 2009 cohort. To me, JPFP represented more than just a nice paycheck that started me off the track of research independence. Instead, it also provided a supportive community and network where I met many other wonderful JPFP fellows... 4/
As a person, she was warm, kind, and inspiring. I had the honor of meeting her at our annual fellowship symposia.
The Jenkins Pre-doctoral Fellowship program was established in 2000 in her name, awarding PhD fellowships to qualifying grad students including underrepresented groups. 3/
The Jenkins Pre-doctoral Fellowship program was established in 2000 in her name, awarding PhD fellowships to qualifying grad students including underrepresented groups. 3/
July 2, 2025 at 8:40 PM
As a person, she was warm, kind, and inspiring. I had the honor of meeting her at our annual fellowship symposia.
The Jenkins Pre-doctoral Fellowship program was established in 2000 in her name, awarding PhD fellowships to qualifying grad students including underrepresented groups. 3/
The Jenkins Pre-doctoral Fellowship program was established in 2000 in her name, awarding PhD fellowships to qualifying grad students including underrepresented groups. 3/
I was cleaning up my grad-school pile that hasn't been touched for years and found this gem: a beautifully framed recognition for my NASA Harriett G. Jenkins Pre-doctoral Fellowship.
Who was Harriett G. Jenkins and what was this fellowship, you may ask? 1/
Who was Harriett G. Jenkins and what was this fellowship, you may ask? 1/
July 2, 2025 at 8:40 PM
I was cleaning up my grad-school pile that hasn't been touched for years and found this gem: a beautifully framed recognition for my NASA Harriett G. Jenkins Pre-doctoral Fellowship.
Who was Harriett G. Jenkins and what was this fellowship, you may ask? 1/
Who was Harriett G. Jenkins and what was this fellowship, you may ask? 1/
We celebrated undergrad Hajar Aziz's next adventure - PhD program at UCR - with a fun U group lunch. Look at those beaming faces! 😁
June 27, 2025 at 10:23 PM
We celebrated undergrad Hajar Aziz's next adventure - PhD program at UCR - with a fun U group lunch. Look at those beaming faces! 😁
One cool result is that our energy budget calculations show a remarkable agreement between the kinetic power of cluster winds and the energy of the galactic superwind, suggesting that star clusters are the primary drivers of the large-scale wind (even if it pains me to say it as an AGN person 😂).
June 25, 2025 at 12:34 AM
One cool result is that our energy budget calculations show a remarkable agreement between the kinetic power of cluster winds and the energy of the galactic superwind, suggesting that star clusters are the primary drivers of the large-scale wind (even if it pains me to say it as an AGN person 😂).
We color-coded our IFU data with modelled photoionization-shock mixing sequence on the BPT, which we analyzed in the context of star clusters identified and catalogued by HST and JWST. An anticorrelation can be seen between shock fraction vs. local surface number density of star clusters.
June 25, 2025 at 12:34 AM
We color-coded our IFU data with modelled photoionization-shock mixing sequence on the BPT, which we analyzed in the context of star clusters identified and catalogued by HST and JWST. An anticorrelation can be seen between shock fraction vs. local surface number density of star clusters.
We combined wide-field IFU observations from Keck/KCWI + VLT/MUSE of VV114, a nearby galaxy merger undergoing intense star formation and galactic-scale feedback, to unveil the complex dynamics of this system. Broad components (~100-300 km/s) indicated mix of stellar ionization and radiative shocks.
June 25, 2025 at 12:34 AM
We combined wide-field IFU observations from Keck/KCWI + VLT/MUSE of VV114, a nearby galaxy merger undergoing intense star formation and galactic-scale feedback, to unveil the complex dynamics of this system. Broad components (~100-300 km/s) indicated mix of stellar ionization and radiative shocks.
In light of NSF being kicked out of their building, maybe it's a great time to highlight some of our group's work as funded by NSF: postdoc Justin Kader's newly accepted paper "Shockingly Effective: Cluster Winds as Engines of Feedback in Starburst Galaxy" dropped on arXiv 🔭
arxiv.org/abs/2506.16624
arxiv.org/abs/2506.16624
June 25, 2025 at 12:34 AM
In light of NSF being kicked out of their building, maybe it's a great time to highlight some of our group's work as funded by NSF: postdoc Justin Kader's newly accepted paper "Shockingly Effective: Cluster Winds as Engines of Feedback in Starburst Galaxy" dropped on arXiv 🔭
arxiv.org/abs/2506.16624
arxiv.org/abs/2506.16624
Wait, usually the aurora forecast would cover most of the US, stopping just short of southern California (where I live). And now that I'm in Alaska, this is the forecasted map?! I see how it is... 😠😭
June 12, 2025 at 12:33 PM
Wait, usually the aurora forecast would cover most of the US, stopping just short of southern California (where I live). And now that I'm in Alaska, this is the forecasted map?! I see how it is... 😠😭
Don’t miss our interactive AGN SIG session TODAY at 10am AK! Come to Egan Rm 11/12 to learn about the progress we’ve made since the last Astro2020, the upcoming NASA mission capabilities, and where we go from here. #AAS246 🔭
cor.gsfc.nasa.gov/copag/meetin...
cor.gsfc.nasa.gov/copag/meetin...
June 10, 2025 at 4:27 PM
Don’t miss our interactive AGN SIG session TODAY at 10am AK! Come to Egan Rm 11/12 to learn about the progress we’ve made since the last Astro2020, the upcoming NASA mission capabilities, and where we go from here. #AAS246 🔭
cor.gsfc.nasa.gov/copag/meetin...
cor.gsfc.nasa.gov/copag/meetin...
Come one come all - Roman Call for Proposals splinter session is happening now! Egan Rm 11/12 is a bit hidden - head down stairs and circle to the back hallway. @nancyromansci.bsky.social #AAS246 🔭
June 9, 2025 at 8:35 PM
Come one come all - Roman Call for Proposals splinter session is happening now! Egan Rm 11/12 is a bit hidden - head down stairs and circle to the back hallway. @nancyromansci.bsky.social #AAS246 🔭
joining everyone else here on bsky
June 5, 2025 at 10:24 PM
joining everyone else here on bsky
TIL: Adobe Acrobat has a "previous view" button within the "other tools" menu that you can pin to the toolbar, allowing you to easily go back to where you were before you e.g. followed a hyperlink.
May 10, 2025 at 12:07 AM
TIL: Adobe Acrobat has a "previous view" button within the "other tools" menu that you can pin to the toolbar, allowing you to easily go back to where you were before you e.g. followed a hyperlink.
Has it only been 102 days?
May 3, 2025 at 12:47 AM
Has it only been 102 days?
Using (not always science ready) archival data, Tianmu carefully matched the multiwavelength dataset, located the centers (not always easy in mergers), made and fit SEDs to isolate the AGN properties in their most actively growing phase - close SMBH pairs might not be active at the same time!
April 25, 2025 at 3:49 PM
Using (not always science ready) archival data, Tianmu carefully matched the multiwavelength dataset, located the centers (not always easy in mergers), made and fit SEDs to isolate the AGN properties in their most actively growing phase - close SMBH pairs might not be active at the same time!