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Research

Throughout my academic journey, I highly emphasised involving myself in various projects to gain expertise on a diverse range of skills as well as topics. What drives my explorations is the urge to solve the inverse problem through various techniques to answer various astrophysical problems.

Page Last Updated: 23rd Jan 2024

One of the VLT Unit telescopes with its yellow lasers firing up the sky in night.

Active Research Interests

Projects

Spatially resolving star-formation in galaxies

at Cosmic Noon with JWST NIRISS

Master Thesis Student
Max Planck Institute for Astronomy, Heidelberg, Germany Adviser: Dr. Leindert Boogaard & Dr. Fabian Walter

05/2023‐Present

  • Cosmic Noon (1<z<3) is a special period in our Universe's history when both the Star Formation Rate Density (SFRD) and Black Hole Accretion Rate Densities (BHARD) are observed to peak around z~2. This means that the Universe witnessed a peak in the rate of stars forming in the galaxies and also the matter accreted by Supermassive Black Holes. After that, both rates rapidly dropped. 

 

 

 

 

 

 

 

 

 

  • The galaxies we observe today or in our local universe were not used to look like this all the time. Galaxies during the Cosmic Noon had clumpier and thicker disks, distributed star formation,  and more random but slightly ordered motion. 

  • Nelson+16 found that galaxies during cosmic noon appear to be growing inside-out and majorly building up their bulges and Matharu+22 commented on the quenching following inside-out growth via star-formation.

  • To trace this peak of SFRD, we need to observe and analyse the Hα emission caused by the O and B stars in the galaxy and, hence, serve as a tracer for the star formation happening inside the galaxy.

  • With the HST, we could only observe this Hα for the galaxies till z~1.7; hence, the galaxies at the SFRD peak could not be studied. But with JWST, its NIR slitless spectroscopy allows us to observe galaxies with 0.5<z<2.5, covering almost the whole cosmic noon region. Slitless spectroscopy is a clever technique to get low-res spectras of all the galaxies in the whole FoV of your instrument.

  • Therefore, my task in this project is to trace the inside‐out growth, redshift evolution in the stellar mass surface density and dust attenuation in star‐forming galaxies at z=0.5‐2.5 using spatially resolved Hα and Hβ maps measured from JWST’s NIRISS slitless spectroscopy on GOODS‐S field acquired from the NGDEEP survey.

Galaxies from the CLEAR survey showcasing Stellr continuum emission in the left column and their Ha distribution in the right column. (Matharu et al. 2022)

Simulated Ha and Stellar continuum spatial distribution of galaxies at z=2 from the TNG50 simulation. (Pillepich et al. 2019)

Inside-out Quenching of star formation following in the wake of inside-out growth of galaxy via star formation. (Matharu et al. 2022)

Fermi-LAT Collaboration 2018

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Simulated NIRCam (left-most columns) and NIRISS (rest 3 columns) observations of a strongly lensed z=2 galaxy (in the yellow box on top in the NIRCam thumbnail) showcasing how the galaxy is dispersed using a GRISM in two directions to effectively extract their spectra. (Willott et al. 2022)

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Grizli extracts emission line thumbnails, 1D spectra, and best-fit z from the dispersed grism spectra as shown in the above picture. (Matharu et al. 2023)

Testing the FCU for ELT’s MICADO in NIR

Research Assistant
Max Planck Institute for Astronomy
Heidelberg, Germany Adviser: Dr. Robert J. Harris & Dr. Jörg‐Uwe Pott

08/2022‐08/2023

  • Tested the Flat‐field and wavelength Calibration Unit (FCU) prototype for ELT’s Multi‐AO Imaging Camera for Deep Observations (MICADO) in the wavelength range of 0.7 − 2.4 μm to assess if the design meets the quality criterion for calibrations.

  • Simulated the Global Uniformity pattern for different designs in different configurations and compared them with the test results to constrain defects and other factors affecting the uniformity and, therefore, calibration quality.

  • Gained invaluable experience in working at the optics lab with two different Near‐IR cameras and other instruments.

  • Summarised results in a detailed technical report for the MICADO team at MPIA and, based on the test results, prepared a testing plan for the final FCU hardware.

Königstuhl Observatory Opto‑mechatronics Laboratory (KOOL)

Research Assistant
Max Planck Institute for Astronomy
, Heidelberg, & Universität Stuttgart, Stuttgart, Germany
Adviser: Pascal Jaufmann, MSc. & Dr. Jörg‐Uwe Pott

05/2023‐Present

KOOL logo with KOOL written in caps and the logo has both a color and blur horizontal gradient, chaning from blurred blue in left to clear red in right.

The KOOL testbed at MPIA. (Credits: Pascal Jaufmann, MSc.)

The SLM generating a 3rd order Zernike mode as seen by a polarizer card.

  • KOOL is an Adaptive Optics (AO) testbed situated in the KOOL lab at MPIA. The testbed has a fibre-fed LASER source that acts as a star, a Spatial Light Modulator (SLM) for creating a diverse range of wavefront distortions, a Shack-Harmann Wavefront Sensor (WFS) for sensing distorted wavefronts, a Tip-Tilt mirror (TTM) for correcting tip-tilt aberration, a Deformable Mirror (DM) for correcting high-order aberrations and finally, a camera to measure the PSF.

  • As an RA, I assist the KOOL team in the development of controlled AO tests for wind‑induced image magnification stabilisation for the Extremely Large Telescope and document operation manuals of testbed instruments such as the SLM.

Bayesian Analysis of Eclipsing Binaries

Undergraduate Research Assistant

Villanova University, Villanova, PA, U.S.A

Adviser: Dr. Kyle E. Conroy

09/2020 ‐ 10/2021

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  • Tested Inverse Problem solver suite of the PHOEBE eclipsing binary (EB) code with photometric time‐series data from Kepler and TESS and compared its efficiency and accuracy to reproduce the published results done previously using other model fitting codes such as jktebop, ellc.

  • Tested the then in‐development functionalities of the code and provided feedback on model caveats through statistical analysis of discrepancies in the fitted parameters given by various models such as ellc, jktebop, EBAI, PHOEBE to help in the development of the PHOEBE code.

  • Gained extensive experience in Python programming, model optimization, and Bayesian sampling.

  • Gave talks on the project and later also mentored a group of 5 students to use PHOEBE and solve inverse problems.

Binaries: Study and Analysis

Summer Research Intern

Indian Institute of Technology, Bombay, India

Mentor: Mr. Vedant Shenoy

05/2020 ‐ 08/2020

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  • I gained experience in solving the two-body problem and various binary star systems, especially focusing on the Stellar Eclipses’ geometry and mathematics using Python and C++-based integrators.

  • Created Python pipelines to model and analyze the Radial Velocity (RV) curves of Spectroscopic Binaries (SBs) in both circular and elliptical orbits using non‐linear regression and χ2 reduction.

Effects of Coronal Mass Ejections on Earth's Thermosphere

​Bachelor’s Thesis Student
Fergusson College (Autonomous), Pune, India Adviser: Dr. Raka V. Dabhade, Dr. Pratibha B. Mane

08/2019 ‐ 02/2020

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  • Conducted a detailed study on Coronal Mass Ejections (CMEs), Thermospheric Aerosols, Mie Scattering, Twilight Air Glow phenomena, and its occurrence with respect to CMEs.

  • Did an intensive analysis of the archived data of Aerosol No. Density (AND) and high-energy proton flux were used to determine a correlation between a CME hit and AND variation.

  • Determined the possible correlation between a CME hit and Aerosol No. Density (AND) variation from archival data plots of AND and High‑energy Proton Flux.

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