A5039870273- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Astro and Planetary Science
- Planetary Science and Exploration
- History and Developments in Astronomy
- Calibration and Measurement Techniques
- Scientific Research and Discoveries
- Atmospheric Ozone and Climate
- Astrophysics and Cosmic Phenomena
- Spectroscopy and Laser Applications
- Impact of Light on Environment and Health
- CCD and CMOS Imaging Sensors
- Geological and Geochemical Analysis
- Optical Systems and Laser Technology
- Computational Physics and Python Applications
- Geochemistry and Geologic Mapping
- Remote Sensing in Agriculture
- Black Holes and Theoretical Physics
- Astronomical and nuclear sciences
Pontificia Universidad Católica de Chile
2015-2024
NSF’s NOIRLab
2022
Gemini South Observatory
2020-2022
University of Toronto
2020
European Southern Observatory
2018
Hospital Clínico de la Universidad Católica
2017
Herzberg Institute of Astrophysics
2006-2015
National Research Council Canada
2006-2015
Millennium Institute of Astrophysics
2015
National Institute for Astrophysics
2014
ABSTRACT The Next Generation Virgo Cluster Survey (NGVS) is a program that uses the 1 deg 2 MegaCam instrument on Canada–France–Hawaii Telescope to carry out comprehensive optical imaging survey of cluster, from its core virial radius—covering total area 104 —in u * griz bandpasses. Thanks dedicated data acquisition strategy and processing pipeline, NGVS reaches point-source depth g ≈ 25.9 mag (10σ) surface brightness limit μ ∼ 29 arcsec −2 (2σ above mean sky level), thus superseding all...
We report the discovery of 158 previously undetected dwarf galaxies in Fornax cluster central regions using a deep coadded $u, g$ and $i$-band image obtained with DECam wide-field camera mounted on 4-meter Blanco telescope at Cerro Tololo Interamerican Observatory as part {\it Next Generation Survey} (NGFS). The new have quasi-exponential light profiles, effective radii $0.1\!<\!r_e\!<\!2.8$ kpc average surface brightness values $22.0\!<\!\mu_i\!<\!28.0$ mag arcsec$^{-2}$. confirm existence...
We investigate the origin of shape globular cluster (GC) system scaling parameters as a function galaxy mass, i.e. specific frequency (S N ), luminosity L mass M and number ( T ) GCs.In low-mass regime (M V -16 mag) our analysis is based on HST/ACS observations GC populations faint, mainly late-type dwarf galaxies in low-density environments.In order to sample entire range = -11 -23 mag 10 6 -10 11 environment, morphology we augment with data spiral elliptical from literature, which old GCs...
The Pan-Andromeda Archaeological Survey is a survey of $>400$ square degrees centered on the Andromeda (M31) and Triangulum (M33) galaxies that has provided most extensive panorama $L_\star$ galaxy group to large projected galactocentric radii. Here, we collate summarise current status our knowledge substructures in stellar halo M31, discuss connections between these features. We estimate 13 distinctive were produced by at least 5 different accretion events, all last 3 or 4 Gyrs. suggest few...
We examine the nuclear morphology, kinematics, and stellar populations in nearby S0 galaxy NGC 404 using a combination of adaptive optics assisted near-IR integral-field spectroscopy, optical Hubble Space Telescope imaging. These observations enable study nucleus at level detail possible only nearest galaxies. The surface brightness profile suggests presence three components: bulge, star cluster (NSC), central light excess within radii < 3 pc. components have distinct kinematics with modest...
We present color-magnitude diagram analysis of deep Hubble Space Telescope imaging a mass-limited sample 18 intermediate-age (1 - 2 Gyr old) star clusters in the Magellanic Clouds, including 8 for which new data was obtained. find that ${\it all}$ our feature extended main sequence turnoff (eMSTO) regions are wider than can be accounted by simple stellar population (including unresolved binary stars). FWHM widths MSTOs indicate age spreads 200-550 Myr. evaluate dynamical evolution with and...
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...
We conduct a comprehensive numerical study of the orbital dependence harassment on early-type dwarfs consisting 168 different orbits within realistic, Virgo-like cluster, varying in eccentricity and pericentre distance. find is only effective at stripping stars or truncating their stellar disks for that enter deep into cluster core. Comparing to distribution cosmological simulations, we majority (more than three quarters) result no mass loss. also effects radial profiles globular systems...
A particular population of galaxies have drawn much interest recently, which are as faint typical dwarf but the sizes large $L^*$ galaxies, so called "ultra-diffuse galaxie" (UDGs). The lack tidal features UDGs in dense environments suggests that their host halos perhaps massive Milky Way. On other hand, galaxy formation efficiency should be higher such masses. Here we use model catalog generated by populating two simulations: Millennium-II cosmological simulation and Phoenix simulations 9...
We present scaling relations between structural properties of nuclear star clusters and their host galaxies for a sample early-type dwarf observed as part the Hubble Space Telescope (HST) Advanced Camera Surveys (ACS) Coma Cluster Survey.We have analysed light profiles 200 in magnitude range 16.0 < m F814W 22.6 mag, corresponding to -19.0 M -12.4 mag.Nuclear are detected 80 per cent galaxies, thus doubling HST-observed with clusters.We confirm that cluster detection fraction decreases...
We report on a large-scale study of the distribution globular clusters (GCs) throughout Virgo cluster, based photometry from Next Generation Cluster Survey, large imaging survey covering Virgo's primary subclusters to their virial radii. Using g', (g'-i') color-magnitude diagram unresolved and marginally-resolved sources, we constructed 2-D maps GC distribution. present clearest evidence date showing difference in concentration between red blue GCs over extent where (metal-rich) are largely...
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 reliably extend the stellar mass-size relation over $0.2\leq z \leq2$ to low mass galaxies by combining depth of Hubble Frontier Fields (HFF) with large volume covered CANDELS. Galaxies are simultaneously modelled in multiple bands using tools developed MegaMorph project, allowing robust size (i.e., half-light radius) estimates even for small, faint, and high redshift galaxies. show that above 10$^7$M$_\odot$, star-forming well represented a single power law on plane our entire range....
An analysis of ages, metallicities, and [ α/Fe] ratios globular cluster systems in early-type galaxies is presented, based on Lick index measurements summarized Puzia et al. (2004, A&A, 415, 123, Paper I this series). In the light calibration measurement uncertainties, age-metallicity degeneracy, relative dynamic range indices, as well systematics introduced by abundance ratio variations (in particular ratios), we find that most reliable age indicator for our dataset a combination...
Intracluster stellar populations are a natural result of tidal interactions in galaxy clusters. Measuring these is difficult, but important for understanding the assembly most massive galaxies. The Coma cluster one nearest truly clusters, and host to correspondingly large system globular clusters (GCs). We use imaging from HST/ACS Cluster Survey present first definitive detection population intracluster GCs (IGCs) that fills core not associated with individual GC surface density profile...
(Abridged) Using luminosities and structural parameters of globular clusters (GCs) in the nuclear regions (nGCs) low-mass dwarf galaxies from HST/ACS imaging we derive present-day escape velocities (v_esc) stellar ejecta to reach cluster tidal radius compare them with those Galactic GCs extended (hot) horizontal branches (EHBs-GCs). For EHB-GCs, find a correlation between v_esc their metallicity as well (V-I)_0 colour. The similar v_esc, distribution nGCs EHB-GCs implies that could also have...
We present new integrated light spectroscopy of globular clusters (GCs) in NGC 5128, a nearby giant elliptical galaxy less than 4 Mpc away, order to measure radial velocities and derive ages, metallicities, alpha-element abundance ratios. Using the Gemini South 8 meter telescope with instrument Multi-Object Spectrograph, we obtained range ∼3400–5700 Å for 72 GCs signal-to-noise ratio greater 30 Å−1; have also discovered 35 within 5128 from our velocity measurements. measured compared Lick...
We discuss new photometry from high-resolution images of 7 intermediate-age (1-2 Gyr) star clusters in the Large Magellanic Cloud taken with Advanced Camera for Surveys on board Hubble Space Telescope. fit color-magnitude diagrams (CMDs) several different sets theoretical isochrones, and determine systematic uncertainties population parameters when derived using any one set isochrones. The cluster CMDs show interesting features, including extended main sequence turnoff (MSTO) regions, narrow...
The origin of ultra-compact dwarfs (UCDs; rh ≳ 10 pc)—objects larger and more massive than typical globular clusters (GCs), but compact dwarf galaxies—has been hotly debated in the 15 years since their discovery. Even whether UCDs should be considered galactic origin, or simply most extreme star clusters, is not yet settled. We present dynamical properties 97 spectroscopically confirmed 911 GCs associated with central cD galaxy Virgo cluster, M87. Our UCDs, which 89% have M⋆ 2× 106 M☉ 92%...
The NGVS-IR project (Next Generation Virgo Survey - Infrared) is a contiguous near-infrared imaging survey of the cluster galaxies. It complements optical wide-field (NGVS). current state consists Ks-band 4 deg^2 centered on M87, and J 16 covering region between M49 M87. In this paper, we present observations central Virgo's core region. data were acquired with WIRCam Canada-France-Hawaii Telescope total integration time was 41 hours distributed in 34 tiles. A survey-specific strategy...
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...
We present the VST Early-type GAlaxy Survey (VEGAS), which is designed to obtain deep multiband photometry in g, r, i, of about one hundred nearby galaxies down 27.3, 26.8, and 26 mag/arcsec^2 respectively, using ESO facility VST/OmegaCAM. The goals survey are 1) map light distribution up ten effective radii, r_e, 2) trace color gradients surface brightness fluctuation out a few r_e for stellar population characterization, 3) full census satellite systems (globular clusters dwarf galaxies)...
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...