- ID:
- ivo://CDS.VizieR/J/ApJ/788/77
- Title:
- Milky Way L/T/M-dwarfs identified in BoRG survey
- Short Name:
- J/ApJ/788/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a tally of Milky Way late-type dwarf stars in 68 Wide Field Camera 3 (WFC3) pure-parallel fields (227 arcmin^2^) from the Brightest of Reionizing Galaxies survey for high-redshift galaxies. Using spectroscopically identified M-dwarfs in two public surveys, the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey and the Early Release Science mosaics, we identify a morphological selection criterion using the half-light radius (r_50_), a near-infrared J-H, G-J color region where M-dwarfs are found, and a V-J relation with M-dwarf subtype. We apply this morphological selection of stellar objects, color-color selection of M-dwarfs, and optical-near-infrared color subtyping to compile a catalog of 274 M-dwarfs belonging to the disk of the Milky Way with a limiting magnitude of m_F125W_<24(AB). Based on the M-dwarf statistics, we conclude that (1) the previously identified north-south discrepancy in M-dwarf numbers persists in our sample; there are more M-dwarfs in the northern fields on average than in southern ones, (2) the Milky Way's single disk scale-height for M-dwarfs is 0.3-4 kpc, depending on subtype, (3) the scale-height depends on M-dwarf subtype with early types (M0-4) high scale-height (z_0_=3-4 kpc) and later types M5 and above in the thin disk (z_0_=0.3-0.5 kpc), (4) a second component is visible in the vertical distribution, with a different, much higher scale-height in the southern fields compared to the northern ones. We report the M-dwarf component of the Sagittarius stream in one of our fields with 11 confirmed M-dwarfs, seven of which are at the stream's distance. In addition to the M-dwarf catalog, we report the discovery of 1 T-dwarfs and 30 L-dwarfs from their near-infrared colors. The dwarf scale-height and the relative low incidence in our fields of L- and T-dwarfs in these fields makes it unlikely that these stars will be interlopers in great numbers in color-selected samples of high-redshift galaxies. The relative ubiquity of M-dwarfs however will make them ideal tracers of Galactic halo substructure with EUCLID and reference stars for James Webb Space Telescope observations.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/219/15
- Title:
- Morphologies of z=0-10 galaxies with HST data
- Short Name:
- J/ApJS/219/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the redshift evolution of the galaxy effective radius r_e_ obtained from the Hubble Space Telescope (HST) samples of ~190000 galaxies at z=0-10. Our HST samples consist of 176152 photo-z galaxies at z=0-6 from the 3D-HST+CANDELS catalog (Skelton+, 2014, J/ApJS/214/24) and 10454 Lyman break galaxies (LBGs) at z=4-10 identified in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS), HUDF 09/12, and HFF parallel fields, (Harikane+, 2015, in prep) providing the largest data set to date for galaxy size evolution studies. We derive r_e_ with the same technique over the wide redshift range of z=0-10, evaluating the optical-to-UV morphological K correction and the selection bias of photo-z galaxies+LBGs as well as the cosmological surface-brightness dimming effect.
- ID:
- ivo://CDS.VizieR/J/MNRAS/473/663
- Title:
- MUSE and HFFs Photometry of A2744
- Short Name:
- J/MNRAS/473/663
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of Multi Unit Spectroscopic Explorer (MUSE) observations obtained on the massive Frontier Fields (FFs) cluster A2744. This new data set covers the entire multiply imaged region around the cluster core. The combined catalogue consists of 514 spectroscopic redshifts (with 414 new identifications). We use this redshift information to perform a strong-lensing analysis revising multiple images previously found in the deep FF images, and add three new MUSE-detected multiply imaged systems with no obvious Hubble Space Telescope counterpart. The combined strong-lensing constraints include a total of 60 systems producing 188 images altogether, out of which 29 systems and 83 images are spectroscopically confirmed, making A2744 one of the most well-constrained clusters to date. Thanks to the large amount of spectroscopic redshifts, we model the influence of substructures at larger radii, using a parametrization including two cluster-scale components in the cluster core and several group scale in the outskirts. The resulting model accurately reproduces all the spectroscopic multiple systems, reaching an rms of 0.67-arcsec in the image plane. The large number of MUSE spectroscopic redshifts gives us a robust model, which we estimate reduces the systematic uncertainty on the 2D mass distribution by up to ~2.5 times the statistical uncertainty in the cluster core. In addition, from a combination of the parametrization and the set of constraints, we estimate the relative systematic uncertainty to be up to 9 per cent at 200kpc.
- ID:
- ivo://CDS.VizieR/J/A+A/575/A75
- Title:
- MUSE 3D view of HDF-S
- Short Name:
- J/A+A/575/A75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We observed Hubble Deep Field South with the new panoramic integral-field spectrograph MUSE that we built and have just commissioned at the VLT. The data cube resulting from 27h of integration covers one arcmin^2^ field of view at an unprecedented depth with a 1{sigma} emission-line surface brightness limit of 1x10^-19^erg/s/cm2/arcsec2, and contains ~90000 spectra. We present the combined and calibrated data cube, and we performed a first-pass analysis of the sources detected in the Hubble Deep Field South imaging. We measured the redshifts of 189 sources up to a magnitude I_814_=29.5, increasing the number of known spectroscopic redshifts in this field by more than an order of magnitude. We also discovered 26 Ly{alpha} emitting galaxies that are not detected in the HST WFPC2 deep broad-band images. The intermediate spectral resolution of 2.3{AA} allows us to separate resolved asymmetric Ly{alpha} emitters, [OII]3727 emitters, and [CIII]1908 emitters, and the broad instantaneous wavelength range of 4500{AA} helps to identify single emission lines, such as [OIII]5007, H{beta}, and H{alpha}, over a very wide redshift range. We also show how the three-dimensional information of MUSE helps to resolve sources that are confused at ground-based image quality. Overall, secure identifications are provided for 83% of the 227 emission line sources detected in the MUSE data cube and for 32% of the 586 sources identified in the HST catalogue. The overall redshift distribution is fairly flat to z=6.3, with a reduction between z=1.5 to 2.9, in the well-known redshift desert. The field of view of MUSE also allowed us to detect 17 groups within the field. We checked that the number counts of [OII]3727 and Ly{alpha} emitters are roughly consistent with predictions from the literature. Using two examples, we demonstrate that MUSE is able to provide exquisite spatially resolved spectroscopic information on the intermediate-redshift galaxies present in the field. This unique data set can be used for a wide range of follow-up studies. We release the data cube, the associated products, and the source catalogue with redshifts, spectra, and emission-line fluxes.
- ID:
- ivo://CDS.VizieR/J/PASP/125/636
- Title:
- Newly identified star clusters in M 31
- Short Name:
- J/PASP/125/636
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the HST archives, we have searched portions of the southern half and northwest quarter of the Andromeda Galaxy (M 31, NGC 224) for previously unrecognized star clusters. The result is a table of the characteristics of 71 newly identified star clusters. Most are moderately faint, low-mass clusters. Absolute magnitudes range from M(V)=-6.3 to -2.5.
- ID:
- ivo://CDS.VizieR/J/ApJ/699/839
- Title:
- Newly identified star clusters in M33. II.
- Short Name:
- J/ApJ/699/839
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present integrated photometry and color-magnitude diagrams (CMDs) for 161 star clusters in M33, of which 115 were previously uncataloged, using the Advanced Camera For Surveys Wide Field Channel onboard the Hubble Space Telescope. The integrated V-band magnitudes of these clusters range from M_V_~-9 to as faint as M_V_~-4, extending the depth of the existing M33 cluster catalogs by ~1mag. Comparisons of theoretical isochrones to the CMDs using the Padova models yield ages for 148 of these star clusters. The ages range from log(t)~7.0 to log(t)~9.0. Our CMDs are not sensitive to clusters older than ~1Gyr. We find that the variation of the clusters' integrated colors and absolute magnitudes with age is consistent with the predictions of simple stellar population models. These same models suggest that the masses of the clusters in our sample range from 5x10^3^ to 5x10^4^M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/A+A/629/A3
- Title:
- NGC1326A, 1425 and 4548 supergiants VI mags
- Short Name:
- J/A+A/629/A3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Studies on the massive star population in galaxies beyond the Local Group are the key to understand the link between their numbers and modes of star formation in different environments. We present the analysis of the massive star population of the galaxies NGC1326A, NGC 1425 and NGC 4548 using archival Hubble Space Telescope Wide Field Planetary Camera 2 images in the F555W and F814W filters. Through high precision point spread function fitting photometry for all sources in the three fields we identified 7640 candidate blue supergiants, 2314 candidate yellow supergiants, and 4270 candidate red supergiants. We provide an estimation the ratio of blue to red supergiants for each field as a function of galactocentric radius. Using Modules for Experiments in Stellar Astrophysics (MESA) at solar metallicity, we defined the luminosity function and estimated the star formation history of each galaxy. We carried out a variability search in the V and I filters using three variability indexes: the median absolute deviation, the interquartile range, and the inverse von-Neumann ratio. This analysis yielded 243 new variable candidates with absolute magnitudes ranging from M_V_=-4 to -10mag. We classified the variable stars based on their absolute magnitude and their position on the color-magnitude diagram using the MESA evolutionary tracks at solar metallicity. Our analysis yielded 8 candidate variable blue supergiants, 12 candidate variable yellow supergiants, 21 candidate variable red supergiants, and 4 candidate periodic variables.
- ID:
- ivo://CDS.VizieR/J/ApJ/671/1624
- Title:
- NGC 1533 globular cluster candidates
- Short Name:
- J/ApJ/671/1624
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use two-band imaging data from the Advanced Camera for Surveys onboard the Hubble Space Telescope for a detailed study of NGC 1533, an SB0 galaxy in the Dorado group surrounded by a ring of HI.
- ID:
- ivo://CDS.VizieR/J/AJ/133/2737
- Title:
- NGC 3610 globular clusters HST BVI photometry
- Short Name:
- J/AJ/133/2737
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Advanced Camera for Surveys on board the Hubble Space Telescope has been used to obtain deep, high-resolution images of the giant elliptical galaxy NGC 3610, a well-established remnant of a dissipative galaxy merger. These observations supersede previous, shallower observations that revealed the presence of a population of metal-rich globular clusters of intermediate age (~1.5-4Gyr). We detect a total of 580 cluster candidates, 46% more than from the previous WFPC2 images. The new photometry strengthens the significance of the previously found bimodality of the color distribution of clusters.
- ID:
- ivo://CDS.VizieR/J/AJ/133/44
- Title:
- NGC 346 HST VI photometry
- Short Name:
- J/AJ/133/44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the quest to understand how star formation occurs and propagates in the low-metallicity environment of the Small Magellanic Cloud (SMC), we acquired deep F555W (~V) and F814W (~I) Hubble Space Telescope ACS images of the young and massive star-forming region NGC 346. These images and their photometric analysis provide us with a snapshot of the star formation history of the region. We find evidence for star formation extending from ~10Gyr in the past until ~150Myr in the field of the SMC. The youngest stellar population (~3+/-1Myr) is associated with the NGC 346 cluster. It includes a rich component of low-mass pre-main-sequence stars mainly concentrated in a number of subclusters spatially colocated with CO clumps previously detected by Rubio and coworkers. Within our analysis uncertainties, these subclusters appear coeval with each other.
