Vikram Khaire
YOU?
Author Swipe
View article: Reconstructing galactic feedback history via the Lyman-α forest with Habitable Worlds Observatory
Reconstructing galactic feedback history via the Lyman-α forest with Habitable Worlds Observatory Open
Recent studies have focused on the low-$z$ Ly$α$ forest as a potential constraint on galactic feedback, as different AGN and stellar feedback models in hydrodynamic simulations produce varying intergalactic medium (IGM) statistics. However…
View article: The SAP-1 payload: A technology demonstration for space-based microbiology experiments
The SAP-1 payload: A technology demonstration for space-based microbiology experiments Open
View article: Yuti: A General-purpose Transit Simulator for Arbitrary Shaped Objects Orbiting Stars
Yuti: A General-purpose Transit Simulator for Arbitrary Shaped Objects Orbiting Stars Open
We present a versatile transit simulator ( Yuti ) aimed at generating light curves for arbitrarily shaped objects transiting stars. Utilizing a Monte Carlo algorithm, it accurately models the stellar flux blocked by these objects, producin…
View article: Measurements of the thermal and ionization state of the intergalactic medium during the cosmic afternoon
Measurements of the thermal and ionization state of the intergalactic medium during the cosmic afternoon Open
We perform the first measurement of the thermal and ionization state of the intergalactic medium (IGM) across $0.9 \lt z \lt 1.5$ using 301 Ly $\,\alpha$ absorption lines fitted from 12 archival Hubble Space Telescope Space Telescope Imagi…
View article: Lyman Limit System with O vi in the Circumgalactic Environment of a Pair of Galaxies
Lyman Limit System with O vi in the Circumgalactic Environment of a Pair of Galaxies Open
We report on the analysis of a multiphase Lyman limit system (LLS) at z = 0.39047 identified toward the background quasar FBQS J0209–0438. The O VI doublet lines associated with this absorber have a different profile from the low-ionizatio…
View article: Lyman Limit System with O VI in the Circumgalactic Environment of a Pair of Galaxies
Lyman Limit System with O VI in the Circumgalactic Environment of a Pair of Galaxies Open
We report on the analysis of a multiphase Lyman limit system (LLS) at $z=0.39047$ identified towards the background quasar FBQS J0209-0438. The O VI doublet lines associated with this absorber have a different profile from the low ionizati…
View article: Searching for the imprints of AGN feedback on the Lyman alpha forest around luminous red galaxies
Searching for the imprints of AGN feedback on the Lyman alpha forest around luminous red galaxies Open
We explore the potential of using the low-redshift Lyman $\alpha$ (Ly $\alpha$) forest surrounding luminous red galaxies (LRGs) as a tool to constrain active galactic nuclei (AGNs) feedback models. Our analysis is based on snapshots from t…
View article: A General-Purpose Transit Simulator for Arbitrary Shaped Objects Orbiting Stars
A General-Purpose Transit Simulator for Arbitrary Shaped Objects Orbiting Stars Open
We present a versatile transit simulator aimed at generating light curves for arbitrarily shaped objects transiting stars. Utilizing a Monte Carlo algorithm, it accurately models the stellar flux blocked by these objects, producing precise…
View article: FLAME: Fitting Ly<i>α</i>absorption lines using machine learning
FLAME: Fitting Ly<i>α</i>absorption lines using machine learning Open
We introduce FLAME, a machine-learning algorithm designed to fit Voigt profiles to H I Lyman-alpha (Ly α ) absorption lines using deep convolutional neural networks. FLAME integrates two algorithms: the first determines the number of compo…
View article: FLAME: Fitting Ly$α$ Absorption lines using Machine learning
FLAME: Fitting Ly$α$ Absorption lines using Machine learning Open
We introduce FLAME, a machine-learning algorithm designed to fit Voigt profiles to HI Lyman-alpha (Ly$α$) absorption lines using deep convolutional neural networks. FLAME integrates two algorithms: the first determines the number of compon…
View article: The impact of the WHIM on the IGM thermal state determined from the low-<i>z</i> Lyman α forest
The impact of the WHIM on the IGM thermal state determined from the low-<i>z</i> Lyman α forest Open
At z ≲ 1, shock heating caused by large-scale velocity flows and possibly violent feedback from galaxy formation, converts a significant fraction of the cool gas (T ∼ 104 K) in the intergalactic medium (IGM) into warm–hot phase (WHIM) with…
View article: Measurements of the Thermal and Ionization State of the Intergalactic Medium during the Cosmic Afternoon
Measurements of the Thermal and Ionization State of the Intergalactic Medium during the Cosmic Afternoon Open
We perform the first measurement of the thermal and ionization state of the intergalactic medium (IGM) across 0.9 < z < 1.5 using 301 \lya absorption lines fitted from 12 HST STIS quasar spectra, with a total pathlength of Δz=2.1. We emplo…
View article: Searching for the Imprints of AGN Feedback on the Lyman Alpha Forest Around Luminous Red Galaxies
Searching for the Imprints of AGN Feedback on the Lyman Alpha Forest Around Luminous Red Galaxies Open
We explore the potential of using the low-redshift Lyman-$α$ (Ly$α$) forest surrounding luminous red galaxies (LRGs) as a tool to constrain active galactic nuclei (AGN) feedback models. Our analysis is based on snapshots from the Illustris…
View article: Can the low-redshift Lyman alpha forest constrain AGN feedback models?
Can the low-redshift Lyman alpha forest constrain AGN feedback models? Open
We investigate the potential of low-redshift Lyman alpha (Lyα) forest for constraining active galactic nuclei (AGNs) feedback models by analysing the Illustris and IllustrisTNG simulation at z = 0.1. These simulations are ideal for studyin…
View article: The Impact of the WHIM on the IGM Thermal State Determined from the Low-$z$ Lyman-$α$ Forest
The Impact of the WHIM on the IGM Thermal State Determined from the Low-$z$ Lyman-$α$ Forest Open
At $z \lesssim 1$, shock heating caused by large-scale velocity flows and possibly violent feedback from galaxy formation, converts a significant fraction of the cool gas ($T\sim 10^4$ K) in the intergalactic medium (IGM) into warm-hot pha…
View article: Can the Low Redshift Lyman Alpha Forest Constrain AGN Feedback Models?
Can the Low Redshift Lyman Alpha Forest Constrain AGN Feedback Models? Open
We investigate the potential of low-redshift Lyman alpha (Ly$α$) forest for constraining active galactic nuclei (AGN) feedback models by analyzing the Illustris and IllustrisTNG simulation at z=0.1. These simulations are ideal for studying…
View article: Measuring the thermal and ionization state of the low-<i>z</i> IGM using likelihood free inference
Measuring the thermal and ionization state of the low-<i>z</i> IGM using likelihood free inference Open
We present a new approach to measure the power-law temperature density relationship $T=T_0 (\rho/ \bar{\rho })^{\gamma -1}$ and the UV background photoionization rate $\Gamma _{{{{\rm H\, {\small I}}}}{}}$ of the intergalactic medium (IGM)…
View article: How robust are the inferred density and metallicity of the circumgalactic medium?
How robust are the inferred density and metallicity of the circumgalactic medium? Open
Quantitative estimates of the basic properties of the circumgalactic medium (CGM), such as its density and metallicity, depend on the spectrum of incident UV background radiation. Models of UV background are known to have large variations,…
View article: Physical conditions of five O <scp>vi</scp> absorption systems towards PG 1522+101
Physical conditions of five O <span>vi</span> absorption systems towards PG 1522+101 Open
We present the analysis of five O vi absorbers identified across a redshift path of z ∼ (0.6−1.3) towards the background quasar PG 1522+101 with information on five consecutive ionization stages of oxygen from O ii to O vi. The combined HS…
View article: Solar-metallicity gas in the extended halo of a galaxy at <i>z</i> ∼ 0.12
Solar-metallicity gas in the extended halo of a galaxy at <i>z</i> ∼ 0.12 Open
We present the detection and analysis of a weak low-ionization absorber at z = 0.121 22 along the sightline of the blazar PG 1424+240, using spectroscopic data from both HST/COS and STIS. The absorber is a weak Mg ii analogue, with an inci…
View article: Effect of non-equilibrium ionization on derived physical conditions of the high-z intergalactic medium
Effect of non-equilibrium ionization on derived physical conditions of the high-z intergalactic medium Open
Non-equilibrium ionization effects are important in cosmological hydrodynamical simulations but are computationally expensive. We study the effect of non-equilibrium ionization evolution and UV ionizing background (UVB) generated with diff…
View article: Ultraviolet Perspectives on Diffuse Gas in the Largest Cosmic Structures
Ultraviolet Perspectives on Diffuse Gas in the Largest Cosmic Structures Open
The past decade has seen an explosion of discoveries and new insights into the diffuse gas within galaxies, galaxy clusters, and the filaments composing the Cosmic Web. A new decade will bring fresh opportunities to further this progress t…
View article: The power spectrum of the Lyman-α Forest at z &lt; 0.5
The power spectrum of the Lyman-α Forest at z < 0.5 Open
We present new measurements of the flux power-spectrum P(k) of the z < 0.5 H i Lyman-α Forest spanning scales $k \sim 0.001\!-\!0.1\, \mathrm{s \, km}^{-1}$. These results were derived from 65 far-ultraviolet quasar spectra (resolution …
View article: New synthesis models of consistent extragalactic background light over cosmic time
New synthesis models of consistent extragalactic background light over cosmic time Open
We present new synthesis models of the extragalactic background light (EBL)\nfrom far infra-red (FIR) to TeV gamma-rays, with an emphasis on the extreme\nultraviolet (UV) background which is responsible for the observed ionization\nand the…
View article: C IV absorbers tracing cool gas in dense galaxy group/cluster environments
C IV absorbers tracing cool gas in dense galaxy group/cluster environments Open
We present analysis on three intervening H I-C IV absorption systems tracing\ngas within galaxy group/cluster environments, identified in the $HST$/COS\nfar-UV spectra of the background quasars PG $1148+549$ ($z_{abs}=0.00346$),\nSBS~$1122…
View article: Physical conditions in high-<i>z</i> optically thin C <scp>iii</scp> absorbers: origin of cloud sizes and associated correlations
Physical conditions in high-<i>z</i> optically thin C <span>iii</span> absorbers: origin of cloud sizes and associated correlations Open
We present detailed photoionization models of well aligned optically thin C\nIII absorption components at $2.1 < z < 3.4$. Using our models we estimate\ndensity ($n_{\\rm \\tiny H}$), metallicity ($[C/H]$), total hydrogen column\ndensity a…
View article: Detection of low-metallicity warm plasma in a galaxy overdensity environment at z ∼ 0.2
Detection of low-metallicity warm plasma in a galaxy overdensity environment at z ∼ 0.2 Open
We present results from the analysis of a multiphase O VI - broad Ly-alpha absorber at z = 0.19236 in the HST/COS spectrum of PG 1121+422. The low and intermediate ionization metal lines in this absorber have a single narrow component, whe…
View article: Efficient adiabatic hydrodynamical simulations of the high-redshift intergalactic medium
Efficient adiabatic hydrodynamical simulations of the high-redshift intergalactic medium Open
We present a post-processing tool for GADGET-2 adiabatic simulations to model various observed properties of the Ly$\alpha$ forest at $2.5 \leq z \leq 4$ that enables an efficient parameter estimation. In particular, we model the thermal a…
View article: Constraints on QSO emissivity using H i and He ii Lyman α forest
Constraints on QSO emissivity using H i and He ii Lyman α forest Open
The spectrum of cosmic ultraviolet background radiation at He II ionizing energies (E > 4 Ryd) is important to study the He II reionization, thermal history of the intergalactic medium (IGM) and metal lines observed in QSO absorption spect…
View article: Detection of two intervening Ne viii absorbers probing warm gas at z ∼ 0.6
Detection of two intervening Ne viii absorbers probing warm gas at z ∼ 0.6 Open
We report on the detection of two Ne VIII absorbers, at z = 0.61907 and z =\n0.57052 in the HST/COS spectrum of background quasars SDSS J 080908.13+461925.6\nand SBS 1122+594 respectively. The Ne VIII 770 line is at $\\sim 3\\sigma$\nsigni…