- ID:
- ivo://CDS.VizieR/J/A+A/507/1375
- Title:
- HST/ACS VI data of M31 globular clusters
- Short Name:
- J/A+A/507/1375
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With the aim of increasing the sample of M31 clusters for which a colour-magnitude diagram is available, we searched the HST archive for ACS images containing objects included in the Revised Bologna Catalogue of M31 globular clusters (RBC Version 3.5 available at: http://www.bo.astro.it/M31). Sixty-three such objects were found. We used the ACS images to confirm or revise their classification and were able to obtain useful CMDs for 11 old globular clusters and 6 luminous young clusters. We obtained simultaneous estimates of the distance, reddening, and metallicity of old clusters by comparing their observed field-decontaminated CMDs with a grid of template clusters of the Milky Way. We estimated the age of the young clusters by fitting with theoretical isochrones.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/865/33
- Title:
- HST and Chandra obs. of the GLIMPSE-C01 star cluster
- Short Name:
- J/ApJ/865/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of Hubble Space Telescope and Chandra X-Ray Observatory observations of the GLIMPSE-C01 (hereafter GC01) star cluster. Color-magnitude and color-color diagrams suggest a cluster age of >~2Gyr up to ~10Gyr (dependent on GC01's metallicity), a distance of 3.3-3.5kpc, and strong differential reddening with A_V_=14-22. After performing astrometric corrections, we find that nine of the 15 X-ray sources have at least one near-infrared (NIR) counterpart within the 2{sigma} Chandra positional error circles. However, given the very high density of NIR sources in the cluster, most of these counterparts are likely due to chance coincidence. We jointly analyze the X-ray and NIR properties to assess the likelihood of true associations. Based primarily on their X-ray properties, we identify a low-mass X-ray binary candidate (source X2), a cataclysmic variable (CV) candidate (source X1), and an active binary (AB) candidate (source X9). Source X11 is detected during an X-ray flaring episode with a flare luminosity (L_X_=2.1x10^33^erg/s) and has a quiescent luminosity L_X_<8.0x10^30^erg/s, in 0.5-8keV at the distance of GC01, suggesting that the source is either an AB or CV. We also discuss the limits on an intermediate-mass black hole at the center of GC01 and the challenges of X-ray source classification imposed by the limitations of the existing data and instrumentation along with future prospects in the James Webb Space Telescope era.
- ID:
- ivo://CDS.VizieR/J/ApJ/738/186
- Title:
- HST and DEIMOS measurements of NGC 2419 stars
- Short Name:
- J/ApJ/738/186
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of a kinematic data set of stars in the globular cluster NGC 2419, taken with the DEep Imaging Multi-Object Spectrograph at the Keck II telescope. Combined with a reanalysis of deep Hubble Space Telescope and Subaru Telescope imaging data, which provide an accurate luminosity profile of the cluster, we investigate the validity of a large set of dynamical models of the system, which are checked for stability via N-body simulations.
- ID:
- ivo://CDS.VizieR/J/AJ/132/378
- Title:
- HST and UV photometry of NGC 6822
- Short Name:
- J/AJ/132/378
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Hubble Space Telescope WFPC2 and STIS imaging of the low-metallicity galaxy NGC 6822, performed as part of a study of the young stellar populations in the galaxies of the Local Group. Eleven WFPC2 pointings, with some overlap, cover two regions extending over 19 and 13arcmin^2^, respectively, off the galaxy center. The filters used are F170W, F255W, F336W, F439W, and F555W. One 25x25 field observed with the STIS FUV- and NUV-MAMA includes Hodge's OB 8 association and the HII region Hubble V, contained in field 1 of Bianchi et al. (2001, Cat. <J/AJ/121/2020>); this previous study provides additional WFPC2 four-band photometry. We derive the physical parameters of the stars in the fields and the extinction by comparing the photometry to grids of model magnitudes.
- ID:
- ivo://CDS.VizieR/B/hst
- Title:
- HST Archived Exposures Catalog
- Short Name:
- B/hst
- Date:
- 20 Feb 2022 06:00:52
- Publisher:
- CDS
- Description:
- This catalogue is a copy of the Archived Exposures Catalog (AEC) compiled from the Hubble Space Telescope Data Archive database, with an indication about the existence of scientific images or spectra. It provides a summary of completed HST science observations. This catalogue contains also WFPC2 observations stacked into associations which usage is recommended for a large fraction of the WFPC2 images (see details in the "WFPC2 Associations" section below).
6536. HST astrometry of TNOs
- ID:
- ivo://CDS.VizieR/J/ApJS/189/336
- Title:
- HST astrometry of TNOs
- Short Name:
- J/ApJS/189/336
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 1428 individual astrometric measurements of 256 trans-Neptunian objects made with Hubble Space Telescope (HST). The observations were collected over three years with two instruments, the Wide Field Planetary Camera 2 and the Advanced Camera for Surveys High Resolution Camera, as part of four HST programs. We briefly describe the data and our analysis procedures. The submission of these measurements to the Minor Planet Center increased the individual arc length of objects by 1.83 days to 8.11 years. Of the 256 total objects, 62 (24.2%) had arc length increases of >=3 years. The arc length for 60 objects (23.4%) was increased by a factor of 2 or greater.
- ID:
- ivo://CDS.VizieR/J/ApJ/844/164
- Title:
- HST astro-photometric analysis of NGC5139. III.
- Short Name:
- J/ApJ/844/164
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We take advantage of the exquisite quality of the Hubble Space Telescope 26-filter astro-photometric catalog of the core of {omega}Cen presented in the first paper of this series and the empirical differential-reddening correction presented in the second paper in order to distill the main sequence into its constituent populations. To this end, we restrict ourselves to the five most useful filters: the magic "trio" of F275W, F336W, and F438W, along with F606W and F814W. We develop a strategy for identifying color systems where different populations stand out most distinctly, then we isolate those populations and examine them in other filters where their subpopulations also come to light. In this way, we have identified at least 15 subpopulations, each of which has a distinctive fiducial curve through our five-dimensional photometric space. We confirm the MSa to be split into two subcomponents, and find that both the bMS and the rMS are split into three subcomponents. Moreover, we have discovered two additional MS groups: the MSd (which has three subcomponents) shares similar properties with the bMS, and the MSe (which has four subcomponents) has properties more similar to those of the rMS. We examine the fiducial curves together and use synthetic spectra to infer relative heavy-element, light-element, and helium abundances for the populations. Our findings show that the stellar populations and star formation history of {omega} Cen are even more complex than inferred previously. Finally, we provide as a supplement to the original catalog a list that identifies for each star which population it is most likely associated with.
- ID:
- ivo://CDS.VizieR/J/AJ/125/3302
- Title:
- HST binary very low mass stars and brown dwarfs
- Short Name:
- J/AJ/125/3302
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present analysis of Hubble Space Telescope (HST) images of 82 nearby field late M and L dwarfs. We resolve 13 of these systems into double M/L dwarf systems and identify an additional possible binary.
- ID:
- ivo://CDS.VizieR/J/MNRAS/449/2937
- Title:
- HST BVI catalogue of star clusters in 5 HCGs
- Short Name:
- J/MNRAS/449/2937
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a photometric catalogue of star cluster candidates in Hickson compact groups (HCGs) 7, 31, 42, 59, and 92, based on observations with the Advanced Camera for Surveys and the Wide Field Camera 3 on the Hubble Space Telescope. The catalogue contains precise cluster positions (right ascension and declination), magnitudes, and colours in the BVI filters. The number of detected sources ranges from 2200 to 5600 per group, from which we construct the high-confidence sample by applying a number of criteria designed to reduce foreground and background contaminants. Furthermore, the high-confidence cluster candidates for each of the 16 galaxies in our sample are split into two subpopulations: one that may contain young star clusters and one that is dominated by globular older clusters. The ratio of young star cluster to globular cluster candidates varies from group to group, from equal numbers to the extreme of HCG 31 which has a ratio of 8 to 1, due to a recent starburst induced by interactions in the group. We find that the number of blue clusters with M_V_<-9 correlates well with the current star formation rate in an individual galaxy, while the number of globular cluster candidates with M_V_<-7.8 correlates well (though with large scatter) with the stellar mass. Analyses of the high-confidence sample presented in this paper show that star clusters can be successfully used to infer the gross star formation history of the host groups and therefore determine their placement in a proposed evolutionary sequence for compact galaxy groups.
- ID:
- ivo://CDS.VizieR/J/AJ/122/1330
- Title:
- HST BVI photometry of M 81 star clusters
- Short Name:
- J/AJ/122/1330
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present the discovery of 114 compact star clusters in the nearby spiral galaxy M81 from B-, V-, and I-band Hubble Space Telescope Wide Field Planetary Camera 2 imaging in eight fields, covering a total area of ~40arcmin^2^. The fields sample a variety of environments (both spiral and interarm regions), as well as a range of projected galactocentric distances from 2 to 12kpc. The sample is complete to V~22, deeper by ~1mag than any previous cluster survey in M81. We present details of the separation of clusters from both stellar sources and background galaxies, which has been based solely on structural parameters and morphology and not using any color cuts, as is necessary for ground-based surveys. We present magnitudes and colors of detected clusters. Surface brightness profiles are compared with single-mass King models, giving a range of core radii for the clusters in our sample between 0.2 and 7pc.