Introducing Gourav Khullar

Gourav Khullar (@isskywalker, Pronouns: he/him) is a PhD Candidate at the University of Chicago, affiliated with the Dept. of Astronomy and Astrophysics, and the Kavli Institute of Cosmological Physics. An Indian national, he has been in Chicago since 2015, having moved to the US from the University of Cambridge with a masters degree in Astrophysics, and the Indian Institute of Technology, Delhi with a bachelors degree in Engineering Physics.

Gourav’s research focuses on the astrophysics of member galaxies of high-redshift galaxy clusters, which he studies via tools like optical-infrared spectroscopy and strong gravitational lensing. Gourav is part of the South Pole Telescope (SPT) Clusters collaboration, and is also affiliated with the Dark Energy Survey (DES). Counting himself as an observer and an analyst, Gourav is a frequent user of the Magellan Telescopes and the Cerro Tololo Inter-American Observatory (CTIO) in Chile for his research. His past work as an undergraduate and masters student includes an analysis of host galaxy properties in DES-discovered active galactic nuclei (AGN), understanding chemical enrichment in galaxy environments via simulations and observations, spectroscopic studies of Type Ib supernovae, and building stellar speckle interferometric apparatus in a laboratory that mimic adaptive optics systems on telescopes.

Outside astrophysics research, Gourav has also been a part of the Astrobites collaboration since 2015, both as a science communication writer-editor and an education researcher. Gourav also works on issues of social justice, having co-founded initiatives like the Diversity, Equity and Inclusion Journal Club (DEIJC) at UChicago, a platform that helps early-career astrophysicists create an equitable and inclusive local community through peer education. He is an organizer and officer with Graduate Students United – UChicago’s graduate worker union – which has been fighting for labor rights for graduate members of the UChicago community. On a light day, you would find Gourav reading non-fiction books, listening to Punjabi music, or at a movie theatre checking out the latest superhero flick!

Links:

Personal Dept. Page: https://kicp.uchicago.edu/people/profile/gourav_khullar.html

SPT: https://pole.uchicago.edu/public/

DES: https://www.darkenergysurvey.org/scientistoftheweek/gourav-khullar/

Astrobites: https://astrobites.org/

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Introducing Héctor Vives-Arias

Héctor Vives-Arias (@DarkSapiens) obtained his PhD in Physics at the University of Valencia, Spain, using gravitational lenses to study both the structure of quasars and the distribution of dark matter subhaloes. He is currently a postdoc at the Instituto de Astrofísica de Canarias (IAC), where he works with ALMA observations of the active galactic nucleus in NGC 1068 to try to understand the structure and kinematics of the dust and molecular gas surrounding its center.

In his last year as an undergrad he got a summer grant at the IAC, where he analyzed the distribution and velocity of the gas in several nearby active galactic nuclei by working with near infrared integral field spectroscopy data from the SINFONI instrument at the VLT. For his Master’s thesis in Valencia, however, he switched to gravitational lens systems in which quasars were multiply imaged by foreground galaxies. Continuing this work on this PhD thesis, he used observations of the Einstein Cross in the optical and mid infrared (from the CanariCam instrument at the Gran Telescopio Canarias) to determine the size and temperature profile of the accretion disk of the quasar by studying the gravitational microlensing in the system, and also to estimate the amount of substructure in the dark matter halo of the lens galaxy that would produce the non-microlensed flux ratios between the quasar images. He also stayed for about a year at the University of Manchester, where he learned to work with radio interferometry data. There, he processed VLA observations of another lens system in order to measure the flux ratios between the multiple images, and to also determine the size of the radio emitting region.

He is currently working on a study of a dozen quadruply lensed systems to estimate the abundance of dark matter subhaloes from the flux ratios between the quasar images in observations of their narrow line regions, radio cores, and dusty tori, while also analyzing ALMA data of nearby active galactic nuclei to study those dusty tori directly in his recently started postdoc at the IAC.

Despite his research focus on active galaxies and dark matter, his scientific interests are much broader than that, and he always tries to keep learning as much as he can about many different fields. He has a passion for science communication that has helped him remain motivated in the low moments of academic life, and he regularly enjoys explaining science on Twitter, blog articles, radio programs, podcasts, and public talks. Other hobbies include archery, drawing, and 3D animation and rendering.

Introducing Rachael Livermore

Rachael is a British astronomer working at the University of Texas at Austin. She received her Bachelors in Mathematics and Physics with Astrophysics from King’s College London, her Masters in Astronomy from the University of Sussex and her PhD from Durham University before moving to Texas as a postdoc.

Her research focuses on the most distant galaxies, trying to understand how the earliest galaxies formed and the effect they had on the reionization of the Universe in its first billion years. Her specialty is gravitational lensing, whereby galaxies that are seen behind massive galaxy clusters appear magnified.

She is also heavily involved in public outreach as the co-founder and host of Astronomy on Tap ATX (@AoTATX), a series of free astronomy talks held in a bar in Austin. She will be hosting this event for the last time this week.

Rachael usually tweets as @rhaegal.

Introducing Tom Kitching

I am a Lecturer in Astrophysics and a Royal Society University Research Fellow at UCL in London, currently working on dark energy and gravitational lensing. I graduated from Imperial College London (@imperialcollege) and then did a PhD at the University of Edinburgh (@EdinburghUni) on the topic of weak gravitational lensing. After that I was a postdoc at Oxford University (@OxfordAstro) before returning to Edinburgh for further postdoctoral work. I was then awarded a Royal Astronomical Society (@RoyalAstroSoc) postdoctoral Fellowship, and then a Royal Society (@royalsociety) University Research Fellowship. I moved to University College London (@ucl) in 2012 to start my lectureship in Astrophysics at the Mullard Space Science Laboratory (@MSSLSpaceLab).

My research is focused on trying to figure out what dark energy is, using a method called “gravitational lensing”. Gravitational lensing is the effect where light from distance galaxies is curved by the warping of spacetime caused by dark matter. Even though we don’t know what dark matter is, we do know that it lenses galaxy light, like a magnifying glass lenses light on Earth. We can use gravitational lensing to measure the distances to galaxies and also how dark matter has clustered together over time – both are measurements that dark energy strongly influences, hence by measuring gravitational lensing we can learn about dark energy.

My main activities at the current time focus on preparing for a new space mission called Euclid (@EC_Euclid)  Euclid is the next cosmology space mission, due for launch in 2020. It will survey three quarters of the extragalactic sky over three quarters the age of the Universe. I am one of the Science Leads in this mission, and help to coordinate the weak lensing activities.

I am also involved in several public outreach activities. For example I contribute and edit two blogs https://msslastro.wordpress.com and https://lateuniverse.wordpress.com . In 2015 I contributed to a MSSL poetry collaboration, and was a co-author of the anthology of scientific poems that was published (Laboratorio, Sidekick books 2015 ), who’s launch party will be this week!

You can find me rest of the year on Twitter @tom_kitching