A5054174661- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Calibration and Measurement Techniques
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Blind Source Separation Techniques
- Satellite Communication Systems
- Impact of Light on Environment and Health
- Scientific Research and Discoveries
- Food Industry and Aquatic Biology
- Optical Coatings and Gratings
- Historical and socio-economic studies of Spain and related regions
- Scientific Computing and Data Management
- High voltage insulation and dielectric phenomena
- Advanced Electrical Measurement Techniques
- Electromagnetic Scattering and Analysis
- Computational Physics and Python Applications
- Advanced Fiber Optic Sensors
- Spectroscopy and Chemometric Analyses
- Space Exploration and Technology
University of the Pacific
2017-2024
University of California, Santa Cruz
2012-2020
Texas Tech University
2015-2020
University of Colorado Colorado Springs
2012-2018
Carnegie Observatories
2012-2016
Carnegie Institution for Science
2012-2015
National Postdoctoral Association
2014
University of California System
2014
Universidad Complutense de Madrid
2006-2013
University of Central Lancashire
2009
We present a homogeneous set of stellar atmospheric parameters (T eff , log g, [Fe/H]) for MILES, new spectral library covering the range λλ 3525-7500 Å at 2.3 (FWHM) resolution.The consists 985 stars spanning large in parameters, from super-metal-rich, cool to hot, metal-poor stars.The resolution, type coverage and number represent substantial improvement over previous libraries used population synthesis models.The that we here are result previous, extensive compilation literature.In order...
We study the role of environment on galaxy evolution using a sample 868 galaxies in Virgo cluster and its surrounding regions selected from GUViCS Survey with purpose understanding origin red sequence dense environments. collected multifrequency data covering whole electromagnetic spectrum for most galaxies. identify different dynamical substructures composing we calculate local density methods. then distribution belonging to sequence, green valley, blue cloud within substructures. Our...
We present the widest-field resolved stellar map to date of closest ($D\sim3.8$ Mpc) massive elliptical galaxy NGC 5128 (Centaurus A; Cen A), extending out a projected galactocentric radius $\sim150$ kpc. The dataset is part our ongoing Panoramic Imaging Survey Centaurus and Sculptor (PISCeS) utilizing Magellan/Megacam imager. resolve population old red giant branch stars down $\sim1.5$ mag below tip branch, reaching surface brightness limits as low $\mu_{V,0}\sim32$ arcsec$^{-2}$. resulting...
We obtained using MegaCam at the CFHT a deep narrow band Halpha+[NII] wide field image of NGC 4569, brightest late-type galaxy in Virgo cluster. The reveals presence long tails diffuse ionised gas without any associated stellar component extending from disc up to ~ 80 kpc (projected distance) with typical surface brightness few 10^-18 erg s-1 cm-2 arcsec-2. These features provide direct evidence that 4569 is undergoing ram presure stripping event. also shows prominent 8 spur nucleus...
ABSTRACT We report the discovery of DGSAT I, an ultra-diffuse, quenched galaxy located 10.°4 in projection from Andromeda (M31). This low-surface brightness ( μ V = 24.8 mag arcsec −2 ), found with a small amateur telescope, appears unresolved sub-arcsecond archival Subaru/Suprime-Cam images, and hence has been missed by optical surveys relying on resolved star counts, spite its relatively large effective radius R e ) 12″) proximity (15′) to well-known dwarf spheroidal And II. Its red color...
Abstract Using deep, high-resolution optical imaging from the Next Generation Virgo Cluster Survey, we study properties of nuclear star clusters (NSCs) in a sample nearly 400 quiescent galaxies core with stellar masses 10 5 ≲ <?CDATA ${\text{}}{M}_{* }$?> / ${\text{}}{M}_{\odot 12 . The nucleation fraction reaches peak value f n ≈ 90% for 9 and declines both higher lower masses, but nuclei populate as small × Comparison literature data nearby groups shows that at low-mass end is more...
The Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS) is constructing a wide-field map the resolved stellar populations in extended halos these two nearby, prominent galaxies. We present new Magellan/Megacam imaging $\sim3$ deg$^2$ area around A (Cen A), which filled much our coverage to its south, leaving nearly complete halo out projected radius $\sim$150 kpc allowing us identify dwarf have additionally obtained deep Hubble Space Telescope (HST) optical eleven thirteen candidate...
Abstract We present a study of ultra-diffuse galaxies (UDGs) in the Virgo Cluster based on deep imaging from Next Generation Survey. Applying new definition for UDG class galaxy scaling relations, we define samples 44 and 26 UDGs using expansive restrictive selection criteria, respectively. Our sample includes objects that are significantly fainter than previously known UDGs: i.e., more half <?CDATA $\langle \mu {\rangle }_{e}\sim 27.5$?> mag arcsec −2 . The Virgo’s core region show some...
We present new medium resolution kinematic data for a sample of 21 dwarf early-type galaxies (dEs) mainly in the Virgo cluster, obtained with WHT and INT telescopes at Roque de los Muchachos Observatory (La Palma, Spain). These are used to study origin elliptical galaxy population inhabiting clusters. confirm that dEs not dark matter dominated galaxies, least up half-light radius. also find observed outer parts cluster mostly rotationally supported systems disky morphological shapes....
The stellar kinematics of galactic disks are key to constraining disk formation and evolution processes. In this paper, for the first time, we measure age–velocity dispersion correlation in inner 20 kpc (∼3.5 scale lengths) M31 show that it is dramatically different from Milky Way (MW). We use optical Hubble Space Telescope/Advanced Camera Surveys photometry 5800 individual stars Panchromatic Andromeda Treasury survey Keck/DEIMOS radial velocity measurements same Spectroscopic Photometric...
We present Keck-I MOSFIRE near-infrared spectroscopy for a sample of 13 compact star-forming galaxies (SFGs) at redshift 2 ⩽ z 2.5 with star formation rates SFR ∼ 100 M☉ yr−1 and masses log(M/M☉) ∼10.8. Their high integrated gas velocity dispersions σint km s−1, as measured from emission lines Hα [O iii], the resultant M⋆–σint relation M⋆–Mdyn all match well to those quiescent 2, stellar absorption lines. Since log(M⋆/Mdyn) =−0.06 ± 0.2 dex, these SFGs appear be dynamically relaxed evolved,...
The fraction of star-forming to quiescent dwarf galaxies varies from almost infinity in the field zero centers rich galaxy clusters. What is causing this pronounced morphology–density relation? do look like when studied detail, and what conclusions can be drawn about their formation mechanism? Here we study a nearly magnitude-complete sample (−19 < Mr −16 mag) 121 Virgo cluster early types with deep near-infrared images SMAKCED project. We fit two-dimensional models optional inner outer...
ABSTRACT We present measurements of the galaxy luminosity and stellar mass function in a 3.71 deg 2 (0.3 Mpc ) area core Virgo Cluster, based on <?CDATA ${u}^{\ast }$?> griz data from Next Generation Cluster Survey (NGVS). The sample—which consists 352 objects brighter than M g = −9.13 mag, 50% completeness limit survey—reaches 2.2 mag deeper widely used Catalog at least 1.2 any sample previously to measure Virgo. Using Bayesian analysis, we find best-fit faint-end slope α −1.33 ± 0.02 for...
The Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE) is a blind narrow-band H$\alpha$+[NII] imaging survey carried out with MegaCam at the CFHT. During pilot observations we have observed NGC 4330, an intermediate mass, edge-on star forming spiral currently falling into core of cluster. New deep revealed low surface brightness 10 kpc tail exhibiting peculiar filamentary structure. filaments are remarkably parallel one another and clearly indicate direction motion galaxy in...
We analyze the stellar kinematics of 39 dwarf early-type galaxies (dEs) in Virgo cluster. Based on specific angular momentum lambda_e and ellipticity, we find 11 slow rotators 28 fast rotators. The outer parts cluster rotate significantly faster than inner Moreover, 10 out are located 3 degrees (D < 1 Mpc) contain subtle disky structures that visible high-pass filtered optical images, while do not exhibit these structures. In addition, two dEs have kinematically decoupled cores four more...
Abstract The Next Generation Virgo Cluster Survey (NGVS) was designed to provide a deep census of baryonic structures in the cluster. survey covers 104 deg 2 area from core out one virial radius, u * griz bandpasses, point-source depth g ∼ 25.9 mag (10 σ ) and single pixel surface brightness limit μ 29 arcsec −2 (2 above sky). Here we present final catalog 404 galaxies located within 3.71 (0.3 Mpc region centered on M87, Virgo’s dominant galaxy. Of these, 154 were previously uncataloged span...
Abstract We present deep Hubble Space Telescope (HST) imaging of five faint dwarf galaxies associated with the nearby spiral NGC 253 (D ≈ 3.5 Mpc). Three these are newly discovered galaxies, while all were found in Panoramic Imaging Survey Centaurus and Sculptor, a Magellan+Megacam survey to identify dwarfs other substructures resolved stellar light around massive outside Local Group. Our HST data reach ≳3 magnitudes below tip red giant branch for each dwarf, allowing us derive their...
Abstract We have conducted a systematic search around the Milky Way (MW) analog NGC 253 ( D = 3.5 Mpc), as part of Panoramic Imaging Survey Centaurus and Sculptor (PISCeS)—a Magellan+Megacam survey to identify dwarfs other substructures in resolved stellar light MW-mass galaxies outside Local Group. In total, has five satellites identified by PISCeS within 100 kpc with an absolute V -band magnitude M < −7. additionally obtained deep Hubble Space Telescope imaging four reported candidates...
Dwarf galaxies, as the most numerous type of galaxy, offer potential to study galaxy formation and evolution in detail nearby universe. Although they seem be simple systems at first view, remain poorly understood. In an attempt alleviate this situation, MAGPOP EU Research Training Network embarked on a dwarf galaxies named MAGPOP-ITP. paper, we present analysis sample 24 elliptical (dEs) Virgo cluster field, using optical long-slit spectroscopy. We examine their stellar populations...
We report the discovery of a new faint dwarf galaxy, which we dub Scl-MM-Dw1, at projected distance ∼65 kpc from spiral galaxy NGC 253. The results Panoramic Imaging Survey Centaurus and Sculptor (PISCeS), program with Magellan/Megacam imager to study substructure in resolved stellar light around massive galaxies outside Local Group. measure tip red giant branch Scl-MM-Dw1 D = 3.9 ± 0.5 Mpc, consistent that 253, making their association likely. dwarf's population is complex, an old,...
Early-type dwarf galaxies, once believed to be simple systems, have recently been shown exhibit an intriguing diversity in structure and stellar content. To analyze this further, we started the SMAKCED project (Stellar content, MAss Kinematics of Cluster Dwarfs, http://www.smakced.net) obtained deep H-band images for 101 early-type galaxies Virgo a brightness range −19 mag ⩽ Mr −16 mag, typically reaching signal-to-noise ratio 1 per pixel ∼025 at surface brightnesses ∼22.5 arcsec−2 H band....
As part of the Panoramic Imaging Survey Centaurus and Sculptor (PISCeS), we report discovery a pair faint dwarf galaxies (CenA-MM-Dw1 CenA-MM-Dw2) at projected distance ∼90 kpc from nearby elliptical galaxy NGC 5128 (CenA). We measure tip red giant branch to each dwarf, finding D = 3.63 ± 0.41 Mpc for CenA-MM-Dw1 3.60 CenA-MM-Dw2, both which are consistent with 5128. A qualitative analysis color–magnitude diagrams indicates stellar populations consisting an old, metal-poor (≳12 Gyr, [Fe/H] ∼...
We use deep optical photometry from the Next Generation Virgo Cluster Survey [NGVS] to investigate color-magnitude diagram for galaxies inhabiting core of this cluster. The sensitivity NGVS imaging allows us continuously probe galaxy colors over a factor $\sim 2 \times 10^5$ in luminosity, brightest cluster scales overlapping classical satellites Milky Way [$M_{g^{\prime}}$ $\sim$ $-$9; $M_{*}$ 10^6$ M$_{\odot}$], within single environment. Remarkably, we find first evidence that RS flattens...
Abstract We present Keck/DEIMOS spectroscopy of the first complete sample ultradiffuse galaxies (UDGs) in Virgo cluster. select all UDGs that contain at least 10 globular cluster (GC) candidates and are more than 2.5 σ outliers scaling relations size, surface brightness, luminosity (a total UDGs). use radial velocity their GC satellites to measure dispersion each UDG. find a mixed bag galaxies, from one UDG shows no signs dark matter, follow luminosity–dispersion relation early-type most...