About Me
I am a fifth-year Ph.D. candidate at the University of California, Riverside, working with Prof. Gabriela Canalizo to investigate black hole activities in dwarf galaxies. My research is centered on exploring the characteristics of low-mass black holes (< 106 M⊙) and examining their effects on host dwarf galaxies. I employ observational techniques in the visible and near-infrared regions of the electromagnetic spectrum to gain insights into these phenomena.
Before pursuing my doctoral research, I completed a five-year Integrated Bachelor+Master of Science in Physics at Pondicherry University in India. During this time, my research encompassed a range of topics including Radio Astronomy, Astronomical Software, Solar Physics, and Active Galactic Nuclei (AGN).
In addition to my research, I am passionate about teaching, science communication, and astronomy outreach. I am also interested in science policy and would like to get more scientists involved in the government to ensure that policies are informed by scientific expertise and benefit everyone.
CV
Education
Ph.D. in Physics
October 2020 - Present
University of California, Riverside
Understanding the nature and effect of black holes in dwarf galaxies.
Research Interests: Observational Astronomy, AGN, Variability, Integral Field Spectroscopy
BS-MS in Physics (5 year Integrated degree)
July 2015 - May 2020
Pondicherry University, Puducherry, India
Master's Thesis: Modelling the Torus of NGC 1365 using Near-Infrared Emission Spectral Energy Distribution Data
Relevant Research Experience
Summer Intern
May 2019-July 2019
Indian Institute of Astrophysics-Kodaikanal Solar Observatory, Kodaikanal, India
- Magnetic Helicity as a flux storage device and its eruption from solar active regions.
Visiting Summer Student
May 2018-July 2018
Inter University Centre for Astronomy and Astrophysics (IUCAA), Pune, India
- An analysis of Image Detection techniques in Astronomy using Source Extractor and IRAF
Research
Gas outflows in dwarf galaxies are crucial for regulating feedback and shaping star formation processes. Using integral field spectroscopy, we analyzed ionized gas outflows to compare the energetics of those driven by stellar activity versus AGN. In Aravindan et al. 2023, our study revealed that AGN-driven outflows are significantly faster and more energetic than their stellar-powered counterparts. This work aims to provide constraints on AGN feedback models in simulations of dwarf galaxies, offering new insights into their evolution and dynamics.
Detecting low-mass black holes in dwarf galaxies is challenging due to their faint signatures. In Aravindan et al. 2024, we show that MIR variability can reveal AGNs in these galaxies, with 68% of variable MIR sources likely hosting AGNs. In J1205, the lowest-mass galaxy in our sample (log M* = 7.5 M⊙) with a low gas-phase metallicity (12 + log(O/H) = 7.46), we detected a near-infrared coronal line. We also observed broad Paα lines from BLR in two galaxies. We also found that AGN activity causes redder W1-W2 colors in variable galaxies, while star formation dominates in non-variable ones. These findings suggest that MIR variability is a valuable method for identifying AGNs in low-mass galaxies.
JWST's infrared capabilities allow us to investigate AGN-driven outflows in dwarf galaxies in greater detail. Using integral field spectroscopy from NIRSpec, we map the structure of these outflows through line intensity and kinematic maps. We also evaluate their impact on the stellar population using tracers like PAH emission, CN absorption, and CO bands. This study offers the first infrared IFU observations of AGN outflows in dwarf galaxies and could transform our understanding of AGN feedback in low-mass systems.
The impact of ionized gas outflows on other gas phases in dwarf galaxies is not well understood. Using Keck OSIRIS+LGS, we observed star-forming dwarf galaxies with known stellar-driven ionized-gas outflows. We will measure H₂ fluxes, detect molecular outflows, and analyze stellar absorption lines. This study will complement JWST’s analysis of AGN-driven outflows, allowing us to compare the effects of these two mechanisms on molecular content and star formation in dwarf galaxies.
-
First author publications:
A Comparison of Outflow Properties in AGN Dwarfs vs. Star Forming Dwarfs (Archana Aravindan et al. 2023 ApJ 950 33)
A closer look at dwarf galaxies exhibiting MIR variability: AGN confirmation and comparison with non-variable dwarf galaxies (Archana Aravindan et al. 2024)
Teaching
I have been a Teaching Assistant at UCR for several quarters. I have led discussion sections for General Astronomy courses aimed at non-STEM majors and conducted laboratory sessions for undergraduate students in engineering and pre-medical programs. Here is a list of courses I have taught:
- Spring 2024: PHYS 020 - Exploring the Universe: an Adventure in Astronomy
An astronomy course for students from a non-STEM background. Covered the basics of astronomy and astrophysical phenomena, such as solar system, stars, galaxies, black holes and the big bang (discussion). - Winter 2024, Fall 2022: PHYS 006 - The Violent Universe
An introduction to violent phenomena that power the universe, specifically phenomena that illustrate basic astrophysical principles, such as explosions of stars, bursts of star formation, galaxy collisions, black holes, quasars, cosmic jets, and the big bang (discussion). - Summer 2023, Winter 2023, Spring 2022, Winter 2022: PHYS 040B - General Physics
Thermodynamics and Waves (lab). - Fall 2023, Fall 2021: PHYS 02LB - General Physics
Fluid and rotational mechanics, temperature, heat, and electromagnetism (lab). - Spring 2023, Spring 2021: PHYS 040C - General Physics
Electromagnetism (lab). - Winter 2021: PHYS 040A - General Physics
Classical mechanics (lab).
I participated in the ISEE-PDP 2024, where I received comprehensive training in professional skills such as leadership, education, mentoring, project management, collaboration, and communication. The program featured two week-long workshops focused on creating an authentic and inclusive STEM learning experience for college-level students. Following the training, I contributed to the Lick Observatory Community College Training Workshop, where I taught an activity centered on understanding transient events like asteroid occultations and planet transits. This activity utilized light curves constructed using data from the 1-m Nickel telescope and next-generation eVscopes.
Outreach & Science Communication
Science Outreach
I regularly help design and demonstrate affordable and easy-to-replicate astronomy experiments for K-12 children as a part of Camp Highlander at UCR. I also help with telescope viewings for middle and high school students in Riverside County.
Science Communication
I actively try to communicate science to a general audience to foster interest and make it more accessible. Check out my work for Astrobites, a collaboration of astronomy graduate students who take scientific papers and condense them down into bite-sized pieces.
Listen to me talking about my research on black holes and why we need to have faith in astrophysics as a guest on Cosmic Voice, a podcast by Spaceonova.
Science Policy
I am passionate about communicating science to policymakers and advocating for data-driven, evidence-based policy decisions through my involvement with the UCR Science to Policy group.
Check out my policy brief on Anticipatory Diplomacy in Outer Space, published by the Federation of American Scientists.
Science Equity
I am the current Vice-President of POWUR at UCR. Through this group, we hope to create a safe and inclusive space for womxn and minorities in the Physics and Astronomy department at UCR. I host monthly Womxn in Physics coffee socials and have run Book Clubs with high school Physics teachers to explore and discuss the relevance of STEM education to womxn.
Contact Me
Feel free to reach out with questions or for potential collaborations!
Social Profiles
aarav005@ucr.edu