A5070962311- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Adaptive optics and wavefront sensing
- Advanced Fluorescence Microscopy Techniques
- Data Visualization and Analytics
- Remote Sensing in Agriculture
- Mind wandering and attention
- Advanced Vision and Imaging
- Autism Spectrum Disorder Research
- Astro and Planetary Science
- Child Nutrition and Feeding Issues
- Attention Deficit Hyperactivity Disorder
- CCD and CMOS Imaging Sensors
- Leaf Properties and Growth Measurement
- History and Developments in Astronomy
- Photocathodes and Microchannel Plates
- Inertial Sensor and Navigation
- Cosmology and Gravitation Theories
- Scientific Research and Discoveries
Indian Institute of Science Education and Research Mohali
2014-2024
Government Medical College and Hospital
2022
Center for Astrophysics Harvard & Smithsonian
2011-2018
The University of Queensland
2012-2015
University of Birmingham
2009-2012
The SAMI Galaxy Survey will observe 3400 galaxies with the Sydney-AAO Multi-object Integral-field spectrograph (SAMI) on Anglo-Australian Telescope (AAT) in a 3-year survey which began 2013. We present throughput of system, science basis and specifications for target selection, observation plan combined properties selected galaxies. includes four volume limited galaxy samples based cuts proxy stellar mass, along low-stellar mass dwarf all from And Mass Assembly (GAMA) survey. GAMA regions...
In Galaxy And Mass Assembly Data Release 4 (GAMA DR4), we make available our full spectroscopic redshift sample. This includes 248682 galaxy spectra, and, in combination with earlier surveys, results 330542 redshifts across five sky regions covering ~250deg^2. The density, is the highest over such a sustained area, has exceptionally high completeness (95 per cent to r_KIDS=19.65mag), and well suited for study of mergers, groups, low (z<0.25) population. DR4 32 value-added tables or...
We investigate the relationship between stellar and gas specific angular momentum $j$, mass $M_{*}$ optical morphology for a sample of 488 galaxies extracted from SAMI Galaxy Survey. find that measured within one effective radius, monotonically increases with that, $M_{*}>$10$^{9.5}$ M$_{\odot}$, scatter in this relation strongly correlates (i.e., visual classification S\'ersic index). These findings confirm massive all types lie on plane relating mass, light distribution, suggest...
We present the Galaxy And Mass Assembly (GAMA) Panchromatic Data Release (PDR) constituting over 230 deg2 of imaging with photometry in 21 bands extending from far-UV to far-IR. These data complement our spectroscopic campaign 300k galaxies, and are compiled observations a variety facilities including: GALaxy Evolution eXplorer, Sloan Digital Sky Survey, Visible Infrared Telescope for Astronomy (VISTA), Wide-field Survey Explorer, Herschel, GAMA regions currently being surveyed by VLT (VST)...
We use a highly complete subset of the Galaxy And Mass Assembly II (GAMA-II) redshift sample to fully describe stellar mass dependence close pairs and mergers between 108 1012 M⊙. Using analytic form this fit we investigate total accreting on more massive galaxies across all ratios. Depending how conservatively select our robust merging systems, fraction companions is 2.0–5.6 per cent. GAMA-II data see no significant evidence for change in pair z = 0.05 0.2. However, find systematically...
We present a methodology for the regularization and combination of sparse sampled irregularly gridded observations from fibre-optic multiobject integral field spectroscopy. The approach minimizes interpolation retains image resolution on combining subpixel dithered data. discuss in context Sydney–AAO spectrograph (SAMI) Galaxy Survey underway at Anglo-Australian Telescope. SAMI instrument uses 13 fibre bundles to perform high-multiplex spectroscopy across 1° diameter view. is targeting ∼3000...
We explore trends in galaxy properties with Mpc-scale structures using catalogues of environment and large-scale structure from the Galaxy And Mass Assembly (GAMA) survey. Existing GAMA structure, group, pair membership allow us to construct stellar mass functions for different environmental types. To avoid simply extracting known underlying correlations between mass, we create a matched sample galaxies masses within 9.5 ≤ log M*/h−2 M⊙ 11 each population. Using these samples, show that...
We describe the selection of galaxies targeted in eight low-redshift clusters (APMCC0917, A168, A4038, EDCC442, A3880, A2399, A119 and A85; 0.029 < z 0.058) as part Sydney-AAO Multi-Object Integral field spectrograph Galaxy Survey (SAMI-GS). have conducted a redshift survey these using AAOmega multi-object on 3.9-m Anglo-Australian Telescope. The is used to determine cluster membership characterize dynamical properties clusters. In combination with existing data, resulted 21 257 reliable...
Ongoing or recent star formation in galaxies is known to increase with increasing projected distance from the centre of a cluster out several times its virial radius (R v ).Using complete sample (M r ≤ -20.5, 0.02 z 0.15) and around 268 clusters Sloan Digital Sky Survey's Fourth Data Release, we investigate how, at given centre, stellar mass properties galaxy depend on absolute line-of-sight velocity rest frame, |v LOS |.We find that for radii R < 0.5 , fraction high-mass non-brightest...
We take advantage of the first data from Sydney-AAO Multi-object Integral field (SAMI) Galaxy Survey to investigate relation between kinematics gas and stars, stellar mass in a comprehensive sample nearby galaxies. find that all 235 objects our sample, regardless their morphology, lie on tight linking ($M_{*}$) internal velocity quantified by $S_{0.5}$ parameter, which combines contribution both dispersion ($\sigma$) rotational ($V_{rot}$) dynamical support galaxy...
Abstract Based on data from the Galaxy and Mass Assembly (GAMA) survey, we report discovery of structures that refer to as ‘tendrils’ galaxies: coherent, thin chains galaxies are rooted in filaments terminate neighbouring or voids. On average, tendrils contain six span 10 h−1 Mpc. We use so-called line correlation function prove represent real rather than accidental alignments. show voids found Sloan Digital Sky Survey, 7th release survey overlap with GAMA regions a large number galaxies,...
Both theoretical predictions and observations of the very nearby Universe suggest that low-mass galaxies(log10[M*/M⊙] < 9.5) are likely to remain star-forming unless they affected by their local environment. To test this premise, we compare contrast environment both passive galaxies as a function stellar mass, using Galaxy Mass Assembly survey. We find fractions higher in interacting pair group than field at all masses, effect is most apparent lowest mass galaxies. also essentially...
We have analysed the growth of Brightest Group Galaxies and Cluster (BGGs/BCGs) over last 3 billion years using a large sample 883 galaxies from Galaxy And Mass Assembly survey. By comparing stellar mass BGGs BCGs in groups clusters similar dynamical masses, we find no significant between redshift z = 0.27 0.09. also examine number BGGs/BCGs that line emission, finding approximately 65 per cent show Hα emission. From where necessary spectroscopic lines were accurately recovered (54 sample),...
Integrated star formation rate (SFR) and specific (SFR/M*), derived from the spectroscopic data obtained by Sloan Digital Sky Survey (SDSS) release 4 (DR4), are used to show that activity in galaxies (Mr ≤ −20.5) found on outskirts (1–2r200) of some nearby clusters (0.02 z 0.15) is enhanced. By comparing mean SFR a sample with at least one starburst galaxy (log SFR/M* ≥ −10 yr−1and 10 M⊙yr−1) without such ('comparison' clusters), we find despite expected decline towards cluster core, profile...
We analyse Spitzer Multiband Imaging Photometer (MIPS) 24-μm observations, and Sloan Digital Sky Survey Data Release 7 optical broad-band photometry spectra, to investigate the star formation (SF) properties of galaxies residing in Coma supercluster region. find that SF dwarf is quenched only high-density environment at centre clusters groups, but passively evolving massive are found all environments, indicating can become passive via internal processes. The SF–density relation observed for...
I use the spectroscopic data for galaxies in and around nearby (0.02<z<0.06) X-ray bright galaxy clusters, to show that incidence of k+a (or post-starburst) (EW(Ha)<2 ang emission EW(Hd)>3 absorption) may be correlated with accretion small groups clusters. At r<2r200, are found regions higher density relative other cluster galaxies. The have a positively skewed distribution absolute velocity,|v_los|/sigma_v, where v_los is difference between line-of-sight velocity cluster's mean, sigma_v...
We explore the relation between colour (measured from photometry) and specific star formation rate (derived optical spectra obtained by Sloan Digital Sky Survey Data Release 4) of over 6000 galaxies (Mr≤−20.5) in around (<3 r200) low-redshift (z < 0.12) Abell clusters. Even though, as expected, most red sequence have little or no ongoing formation, blue are currently forming stars, there significant populations star-forming passive galaxies. This paper examines various properties belonging...
The Coma supercluster (100 Mpc) offers an unprecedented contiguous range of environments in the nearby Universe. In this paper we present a catalogue spectroscopically confirmed galaxies detected ultraviolet (UV) wavebands. We use arsenal UV and optical data for covering ~ 500 square degrees on sky to study their photometric spectroscopic properties as function environment at various scales. identify different components cosmic-web: large-scale filaments voids using Discrete Persistent...
In this paper we test if nearby blue spheroid (BSphs) galaxies may become the progenitors of star-forming spiral or passively-evolving elliptical galaxies. Our sample comprises 428 various morphologies in redshift range 0.002<z<0.02 (8-87 Mpc) with panchromatic data from Galaxy and Mass Assembly survey. We find that BSph are structurally (mean effective surface brightness, radius) very similar to their red counterparts. However, star-formation other properties such as colour, age metallicity...
In galaxy clusters, efficiently accreting active galactic nuclei (AGNs) are preferentially located in the infall regions of cluster projected phase-space, and rarely found core. This has been attributed to both an increase triggering opportunities for infalling galaxies, a reduction those mechanisms hot, virialized, Exploiting depth completeness (98 per cent at r < 19.8 mag) Galaxy And Mass Assembly survey (GAMA), we probe down group halo mass function assess whether AGNs same groups as they...
We present multi-wavelength global star formation rate (SFR) estimates for 326 galaxies from the Star Formation Reference Survey (SFRS) in order to determine mutual scatter and range of validity different indicators. The widely used empirical SFR recipes based on 1.4 GHz continuum, 8.0 $\mu$m polycyclic aromatic hydrocarbons (PAH), a combination far-infrared (FIR) plus ultraviolet (UV) emission are mutually consistent with $\raise{-0.8ex}\stackrel{\textstyle <}{\sim }$0.3 dex. is even...
There are many proposed mechanisms driving the morphological transformation of disk galaxies to elliptical galaxies. In this paper, we determine if observed in low mass groups can be explained by merger histories We measured group mass-morphology relation for from Galaxy and Mass Assembly catalogue with masses 10$^{11}$ - 10$^{15}$ M$_{\odot}$. Contrary previous studies, fraction our more complete sample increases significantly across full range mass. The at a rate 0.163$\pm$0.012 per dex...
The Herschel Space Observatory has had a tremendous impact on the study of extragalactic dust. Specifically, early-type galaxies (ETG) have been focus several studies. In this paper, we combine results from two studies – Virgo cluster Cluster Survey (HeViCS) and broader, low-redshift Herschel-Astrophysical Terahertz Large Area (H-ATLAS)/Galaxy Mass Assembly (GAMA) contrast dust associated properties for similar mass galaxies. This comparison is motivated by differences in exhibited between...
We employ spectroscopic and photometric data from the Sloan Digital Sky Survey Data Release 7, in a 500-deg2 region, to understand evolution of dwarf [∼(M*+ 2) < Mz M*+ 4] galaxies Coma supercluster (z= 0.023). show that supercluster, red are mostly concentrated dense cores Abell 1367 clusters, galaxy groups embedded filament connecting them. The post-starburst (k+A) dwarfs, however, found infall regions occasionally along filament, suggesting strong velocity fields prevalent vicinity deep...
In this paper we aim to (i) test the number of statistically distinct classes required classify local galaxy population and (ii) identify differences in physical star formation properties visually galaxies. To accomplish this, analyse structural parameters – effective radius (Reff), surface brightness within Reff (〈μ〉e), central (μ0) Sérsic index (n) obtained by fitting light profile 432 galaxies (0.002 < z ≤ 0.02; VikingZ band), their spectral energy distribution using multiband photometry...