Rashmi Gottumukkala
A5079152223- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Cosmology and Gravitation Theories
- Radio Astronomy Observations and Technology
- Geophysics and Gravity Measurements
University of Copenhagen
2024-2025
University of Geneva
2023-2025
DAWN Center for Independent Living
2024
Over the last few years, both ALMA and Spitzer/IRAC observations have revealed a population of likely massive galaxies at $z>3$ that was too faint to be detected in HST rest-frame ultraviolet imaging. However, due very limited photometry for individual galaxies, true nature these so-called HST-dark has remained elusive. Here, we present first sample such observed with deep, high-resolution NIRCam imaging from Early Release Science Program CEERS. 30 sources are selected based on their red...
ABSTRACT Combining the public JWST/NIRCam imaging programs CEERS, PRIMER, and JADES, spanning a total area of $\sim 500\, {\rm arcmin}^2$, we obtain sample $\gt $30 000 galaxies at $z_{\rm phot}\sim 4\!-\!9$ that allows us to perform complete, rest-optical-selected census galaxy population $z\gt 3$. Comparing stellar mass $M_*$ UV-slope $\beta$ distributions between JWST- HST-selected samples, generally find very good agreement no significant biases. Nevertheless, JWST enables probe new...
Abstract The advent of the JWST has revolutionised our understanding high-redshift galaxies. In particular, NIRCam instrument on-board revealed a population red galaxies that had largely evaded detection with HST, potentially due to significant dust obscuration, quiescence, or extreme redshift. Here, we present first NIRSpec spectra 23 red, HST faint dark (H-F444W > 1.75), unveiling their nature and physical properties. This sample includes both dusty quiescent spectroscopic data from...
Context. One of the surprising early findings with JWST has been discovery a strong “roll-over” or softening absorption edge Ly α in large number galaxies at z ≳ 6, addition to systematic offsets from photometric redshift estimates and fundamental galaxy scaling relations. This interpreted as cumulative damped (DLA) wings high column densities neutral atomic hydrogen (H I ), signifying major gas accretion events formation these galaxies. Aims. To explore this new phenomenon systematically,...
ABSTRACT With the advent of JWST, we can probe rest-frame optical emission galaxies at $z\gt 3$ with high sensitivity and spatial resolution, making it possible to accurately characterize red, optically faint thus move towards a more complete census galaxy population redshifts. To this end, present sample 148 massive, dusty from JWST/Cosmic Evolution Early Release Science survey, colour-selected using solely JWST bands. deep JWST/NIRCam data 1.15 4.44 $\mu$m ancillary HST/ACS WFC3 data,...
Combining the public JWST/NIRCam imaging programs CEERS, PRIMER and JADES, spanning a total area of $\sim$500 arcmin$^2$, we obtain sample $>$30,000 galaxies at $z\sim4-9$ that allows us to perform complete, rest-optical selected census galaxy population $z>3$. Comparing stellar mass $M_*$ UV-slope $\beta$ distributions between JWST- HST-selected samples, generally find very good agreement no significant biases. Nevertheless, JWST enables probe small UV-red was missing from previous...
Over the past decade, existence of a substantial population optically invisible, massive galaxies at $z\gtrsim3$ has been implied from mid-infrared to millimeter observations. With unprecedented sensitivity JWST, such extremely galaxy candidates have immediately identified even $z>7$, in much larger numbers than expected. These discoveries raised hot debate. If confirmed, early, high-mass challenge current models formation. However, lack spectroscopic confirmations leads uncertain stellar...
The advent of the JWST has revolutionised our understanding high-redshift galaxies. In particular, NIRCam instrument on-board revealed a population Hubble Space Telescope (HST)-dark galaxies that had previously evaded optical detection, potentially due to significant dust obscuration, quiescence, or simply extreme redshift. Here, we present first NIRSpec spectra 23 HST-dark ($\mathrm{H-F444W>1.75}$), unveiling their nature and physical properties. This sample includes both dusty quiescent...
Some core-collapse supernovae (CCSNe) are too luminous and radiate much total energy to be powered by the release of thermal from ejecta radioactive-decay synthesised $^{56}$Ni/$^{56}$Co. A source additional power is interaction between supernova (SN) a massive circumstellar material (CSM). This an important in Type IIn SNe, which show narrow spectral lines arising unshocked CSM, but not all interacting SNe such lines. We present photometric spectroscopic observations hydrogen-rich SN...
Abstract The dearth of high-quality spectroscopy dusty star-forming galaxies (DSFGs)—the main drivers the assembly dust and stellar mass at peak activity in Universe—greatly hinders our ability to interpret their physical processes evolutionary pathways. We present JWST/NIRSpec observations from RUBIES four submillimeter-selected, Atacama Large Millimeter/submillimeter Array (ALMA)-detected DSFGs cosmic noon, z ∼ 2.3–2.7. While photometry uniformly suggests vigorous ongoing star formation...
We present the first follow-up with JWST of radio-selected near-infrared (NIR)-faint galaxies as part COSMOS-Web survey. By selecting detected at radio frequencies (S_ 3 GHz >11.5 μJy; i.e., S/N$>5$) and faint counterparts NIR wavelengths (F150W$>26.1$ mag), we collected a sample 127 likely dusty star-forming (DSFGs). estimated their physical properties through SED fitting, computed luminosity function for these types sources contribution to total cosmic star formation rate density....
The evolution of galaxy sizes in different wavelengths provides unique insights on build-up across cosmic epochs. Such measurements can now finally be done at z>3 thanks to the James Webb Space Telescope's (JWST) exquisite spatial resolution and multi-wavelength capability. With public data from CEERS, PRIMER-UDS, PRIMER-COSMOS surveys, we measure ∼ 3500 star-forming galaxies $3 z<9$, seven NIRCam bands using model fitting code GalfitM . size--mass relation is measured four redshift...
We present the Red Unknowns: Bright Infrared Extragalactic Survey (RUBIES) providing JWST/NIRSpec spectroscopy of red sources selected across ∼150,arcmin^2 from public JWST/NIRCam imaging in UDS and EGS fields. The novel observing strategy RUBIES offers a well-quantified selection function. survey has been optimised to reach high ($>70%$) spectroscopic completeness for bright F150W-F444W >2) that are very rare. To place these rare context, we simultaneously observed reference sample...
One of the surprising early findings with JWST has been discovery a strong "roll-over" or softening absorption edge Ly$\alpha$ in large number galaxies at ($z\gtrsim 6$), addition to systematic offsets from photometric redshift estimates and fundamental galaxy scaling relations. This interpreted as damped (DLA) wings high column densities neutral atomic hydrogen (HI), signifying major gas accretion events formation these galaxies. To explore this new phenomenon systematically, we assemble...
The emergence of massive, optically-faint galaxies in infrared observations has revealed that our view the high-redshift Universe was previously incomplete. With advent JWST, we can for first time probe rest-frame optical emission at $z>3$ with high sensitivity and spatial resolution, thus moving towards a more complete census galaxy population redshifts. To this end, present sample 148 dusty from JWST/CEERS survey, colour-selected using solely JWST bands. deep JWST/NIRCam data 1.15$μ$m...
The dearth of high quality spectroscopy dusty star-forming galaxies (DSFGs) -- the main drivers assembly dust and stellar mass at peak activity in Universe greatly hinders our ability to interpret their physical processes evolutionary pathways. We present JWST/NIRSpec observations from RUBIES four submillimeter-selected, ALMA-detected DSFGs cosmic noon, $z\sim2.3-2.7$. While photometry uniformly suggests vigorous ongoing star formation for entire sample line with canonical DSFGs, spectra...
We present the Red Unknowns: Bright Infrared Extragalactic Survey (RUBIES), providing JWST/NIRSpec spectroscopy of red sources selected across ~150 arcmin$^2$ from public JWST/NIRCam imaging in UDS and EGS fields. RUBIES novel observing strategy offers a well-quantified selection function: survey is optimised to reach high (>70%) completeness for bright (F150W-F444W>2) that are very rare. To place these rare context, we simultaneously observe reference sample 2<z<7 galaxy population,...
The evolution of galaxy sizes in different wavelengths provides unique insights on build-up across cosmic epochs. Such measurements can now finally be done at $z>3$ thanks to the exquisite spatial resolution and multi-wavelength capability JWST. With public data from CEERS, PRIMER-UDS, PRIMER-COSMOS surveys, we measure $\sim 3500$ star-forming galaxies $3 \leqslant z<9$, 7 NIRCam bands using model fitting code GalfitM. size-mass relation is measured four redshift bins, all bands. We find...