相关论文: The Star Formation Efficiency During Reionization …
The ionizing photon production efficiency, $\xi_{ion}$, is a critical parameter that provides a number of physical constraints to the nature of the early Universe, including the contribution of galaxies to the timely completion of the…
We constrain the rest-UV size-luminosity relation for star-forming galaxies at z~4 and z~6, 7, and 8 identified behind clusters from the Hubble Frontier Fields (HFF) program. The size-luminosity relation is key to deriving accurate…
We have used a sample of 43 star-forming galaxies imaged in the far-ultraviolet (FUV) by the UIT supplemented with 33 galaxies observed by FAUST, to explore the consistency of UV and H alpha derived star formation rates (SFRs). We find,…
We present semi-analytical models of high redshift Lyman-{\alpha} emitters (LAEs) in order to constrain the star formation efficiency in those galaxies. Our supernova feedback induced star formation model along with Sheth-Tormman halo mass…
The James Webb Space Telescope (JWST) has uncovered an abundance of $z>10$ galaxies bright in the ultraviolet (UV) that has challenged traditional theoretical models at high redshifts. Recently, various new models have emerged to address…
Charting the Epoch of Reionization demands robust assessments of what drives the production of ionizing photons in high-redshift star-forming galaxies (SFGs), and requires better predictive capabilities from current observations. Using a…
Galaxy formation during the first billion years of our Universe remains a challenging problem at the forefront of astrophysical cosmology. Although these $z \geq 6$ galaxies are likely responsible for the last major phase change of our…
We study the ionising photon production efficiency at the end of the Epoch of Reionisation ($z \sim 5.4 - 6.6$) for a sample of 30 Lyman-$\alpha$ emitters. This is a crucial quantity to infer the ionising photon budget of the Universe.…
We have used archival ultraviolet (UV) imaging of 50 nearby star-forming galaxies obtained with the Ultraviolet Imaging Telescope (UIT) to derive integrated near-UV and far-UV magnitudes, and have combined these data with H alpha,…
We present the lifetime star formation histories (SFHs) for six ultra-faint dwarf (UFD; $M_V>-7.0$, $ 4.9<\log_{10}({M_*(z=0)}/{M_{\odot}})<5.5$) satellite galaxies of M31 based on deep color-magnitude diagrams constructed from…
We derive apparent and absolute ultraviolet (UV) magnitudes, and luminosities in the infrared (IR) range of a large sample of low-redshift (0<z<1) compact star-forming galaxies (CSFGs) selected from the Data Release 12 of the Sloan Digital…
(Abridged) We review recent observations that suggest the star formation rate density is declining over 3$<z<$7 and illustrate the challenges that this poses in explaining the assembled stellar mass in z$\sim$6 galaxies deduced from Spitzer…
We present measurements of the rest-frame ultraviolet luminosity function at redshifts $z=3$, $z=4$ and $z=5$, using 96894, 38655 and 7571 sources respectively to map the transition between AGN and galaxy-dominated ultraviolet emission…
Acting as powerful gravitational lenses, the strong lensing galaxy clusters of the deep Hubble Frontier Fields (HFF) program permit access to lower-luminosity galaxies lying at higher redshifts than hitherto possible. We analyzed the HFF to…
We present a new technique to estimate the evolution of the very faint end of the UV luminosity function (LF) out to $z\sim5$. Measured star formation histories (SFHs) from the fossil record of Local Group galaxies are used to reconstruct…
We use a well-motivated galaxy formation framework to predict stellar masses, star formation rates (SFR), and ultraviolet (UV) luminosities of galaxy populations at redshifts $z\in 5-16$, taking into account stochasticity of SFR in a…
We use the deep ground-based optical photometry of the Lyman Break Galaxy (LBG) Survey to derive robust measurements of the faint-end slope (alpha) of the UV LF at redshifts 1.9<z<3.4. Our sample includes >2000 spectroscopic redshifts and…
Star formation is evolving very fast in the second half of the Universe, and it is yet unclear whether this is due to evolving gas content, or evolving star formation efficiency (SFE). We have carried out a survey of ultra-luminous galaxies…
Near-infrared VLT data of the GOODS-South area were used to look for galaxies at z=7 down to a limiting magnitude of (J+Ks)AB=25.5. No high-redshift candidates were detected, and this provides clear evidence for a strong evolution of the…
We characterize the evolution of the rest-frame 1500 $\unicode{xC5}$ UV luminosity Function (UVLF) from AstroSat/UVIT F154W and N242W imaging in the Great Observatories Origins Survey North (GOODS-N) field. With deep FUV observations, we…