- ID:
- ivo://CDS.VizieR/J/ApJ/513/34
- Title:
- HDF photometric redshifts catalog
- Short Name:
- J/ApJ/513/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the newly available infrared images of the Hubble Deep Field in the J, H, and K bands and an optimal photometric method, we have refined a technique to estimate the redshifts of 1067 galaxies. A detailed comparison of our results with the spectroscopic redshifts in those cases where the latter are available shows that this technique gives very good results for bright enough objects [AB(814nm)<26.0]. From a study of the distribution of residuals [{Delta}z_rms_/(1+z)~0.1 at all redshifts], we conclude that the observed errors are mainly due to cosmic variance. This very important result allows for the assessment of errors in quantities to be directly or indirectly measured from the catalog. We present some of the statistical properties of the ensemble of galaxies in the catalog, and we finish by presenting a list of bright high-redshift (z~5) candidates extracted from our catalog together with recent spectroscopic redshift determinations confirming that two of them are at z=5.34 and z=5.60.
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- ID:
- ivo://CDS.VizieR/J/A+AS/145/111
- Title:
- HDF-South catalogue of galaxies
- Short Name:
- J/A+AS/145/111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of galaxies in the HDF-S, created using the public version 1 images of the WFPC2 data. We created a catalogue with 4 pass-band (I(814), V(606), B(450), U(300). In V(606), B(450), U(300) and I(814), for each galaxy the catalogue gives photometric parameters. For the I(814), we estimated also the colours and for I(814)<26, the petrosian radius, the mean surface brightness within the petrosian radius, light concentration indexes, that is C_eta_ and C_abr_, and the asymmetry index as computed by Abraham software.
- ID:
- ivo://CDS.VizieR/J/ApJS/166/549
- Title:
- HST/ACS observations of NGC 346
- Short Name:
- J/ApJS/166/549
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a photometric study of the star-forming region NGC 346 and its surrounding field in the Small Magellanic Cloud, using data taken with the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST). The data set contains both short and long exposures for increased dynamic range, and photometry was performed using the ACS module of the stellar photometry package DOLPHOT. We detected almost 100,000 stars over a magnitude range of V~11 to V~28 mag, including all stellar types from the most massive young stars to faint lower main-sequence and pre-main-sequence stars. We find that this region, which is characterized by a plethora of stellar systems and interesting objects, is an outstanding example of mixed stellar populations. We take into account different features of the color-magnitude diagram of all the detected stars to distinguish the two dominant stellar systems: the stellar association NGC 346 and the old spherical star cluster BS 90. These observations provide a complete stellar sample of a field about 5'x5' around the most active star-forming region in this galaxy. Considering the importance of these data for various investigations in the area, we provide the full stellar catalog from our photometry. This paper is the first part of an ongoing study to investigate in detail the two dominant stellar systems in the area and their surrounding field.
- ID:
- ivo://CDS.VizieR/J/ApJS/120/265
- Title:
- HST photometry of M4
- Short Name:
- J/ApJS/120/265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents a detailed description of the acquisition and processing of a large body of imaging data for three fields in the globular cluster M4 taken with the Wide Field and Planetary Camera 2 aboard the Hubble Space Telescope. Analysis with the ALLFRAME package yielded the deepest photometry yet obtained for this cluster. The resulting data set for 4708 stars (positions and calibrated photometry in V, I, and, in two fields, U) spanning approximately six cluster core radii is presented. The scientific analysis is deferred to three companion papers, which investigate the significant white dwarf population discovered and the main-sequence population.
- ID:
- ivo://CDS.VizieR/J/ApJS/122/81
- Title:
- HST snapshot survey of 3CR radio sources
- Short Name:
- J/ApJS/122/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and describe optical counterparts to 46 3CR radio galaxies of redshifts less than 0.1 that were imaged with the Hubble Space Telescope's (HST) WFPC2 camera through the broadband F702W filter as part of the 3CR Snapshot Survey. This is the fifth and last such paper describing the 252 radio galaxies of this R-band survey. At the 0.1'' resolution of the images, a wealth of detail is visible. Approximately 89% of the galaxies are ellipticals, and nearly all reside in groups or clusters of galaxies of various richness and compactness. Nearby elliptical companions of slightly smaller size and mass are common. Dust is prevalent in the cores of the 3C hosts; nearly half of the galaxies possess some type of dust structure, such as irregular dust lanes, filaments, or disks. Besides the well-known dust disks of 3C 264 and 3C 270, we have found five new candidates in 3C 31, 3C 40, 3C 296, 3C 449, and 3C 465, as well as in the central regions of the nearby neighbors of 3C 31 and 3C 465. Our sample includes six confirmed optical synchrotron jets in 3C 15, 3C 66B, 3C 78, 3C 264, 3C 274, and 3C 371, or approximately 13% of the sample. Unresolved nuclei, consistent with the point spread function of WFPC2, are found in 43%-54% of the galaxies and in the majority of galaxies with dust disks and optical jets.
- ID:
- ivo://CDS.VizieR/J/AJ/116/1757
- Title:
- M30 UBV photometry
- Short Name:
- J/AJ/116/1757
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present F555W (V), F439W (B), and F336W (U) photometry of 9507 stars in the central 2' of the dense, post-core-collapse cluster M30 (NGC 7099) derived from Hubble Space Telescope Wide Field Planetary Camera 2 images. These data are used to study the mix of stellar populations in the central region of the cluster. Forty-eight blue straggler stars are identified; they are found to be strongly concentrated toward the cluster center. The specific frequency of blue stragglers, F_BSS_=N(BSS)/N(V<V_HB_+2), is 0.25+/-0.05 in the inner region of M30 (r<20"), significantly higher than the frequency found in other clusters: F_BSS_=0.05-0.15. The shape of M30's blue straggler luminosity function resembles the prediction of the collisional formation model, and is inconsistent with the binary merger model of Bailyn & Pinsonneault (1995ApJ...439..705B). An unusually blue star (B=18.6, B-V=-0.97), possibly a cataclysmic variable based on its color, is found about 1.2" from the crowded cluster center; the photometric uncertainty for this star is large, however, because of the presence of a very close neighbor. Bright red giant stars (B<16.6) appear to be depleted by a factor of 2-3 in the inner r<10" relative to fainter giants, subgiants, and main-sequence turnoff stars (95% significance). We confirm that there is a radial gradient in the color of the overall cluster light, going from B-V~0.82 at r~1' to B-V~0.45 in the central 10". The central depletion of the bright red giants is responsible for about half of the observed color gradient; the rest of the gradient is caused by the relative underabundance of faint red main-sequence stars near the cluster center (presumably a result of mass segregation). The luminosity function of M30's evolved stars does not match the luminosity function shape derived from standard stellar evolutionary models: the ratio of the number of bright giants to the number of turnoff stars in the cluster is 30% higher than predicted by the model (3.8{sigma} effect), roughly independent of red giant brightness over the range M_V_=-2 to +2.
- ID:
- ivo://CDS.VizieR/J/AJ/117/1708
- Title:
- NGC 1741 HST photometry
- Short Name:
- J/AJ/117/1708
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use Hubble Space Telescope (HST) Faint Object Camera (FOC) ultraviolet (UV) and WFPC2 optical images in conjunction with UV spectroscopic observations taken with the Goddard High Resolution Spectrograph to examine the star formation history and properties of the interacting galaxy system NGC 1741 in the Hickson Compact Group 31. The high spatial resolution afforded by HST has allowed us to identify a large number of starburst knots, or "superstar clusters" (SSCs), in the starburst regions of this system. Photometry of these SSCs in the UV and optical bands indicates that most of these objects have ages of a few Myr, with a few up to ~100Myr, and masses between 10^4^ and 10^6^M_{sun}_. The estimated age is confirmed by a spectral synthesis analysis of one knot for which we have obtained a UV spectrum. The V-band luminosity function of the SSCs is well represented by a power law {Phi}(L)~L^-{alpha}^ with an index of -1.85, with no evidence of a turnover brighter than the completeness limit. These properties are in good agreement with those found for SSCs in other starburst galaxies. Our results support the suggestion that some of these SSCs may be extremely young globular clusters formed in a relatively recent starburst episode that has been triggered by a merger event.
- ID:
- ivo://CDS.VizieR/J/ApJS/122/431
- Title:
- Star Clusters in M33
- Short Name:
- J/ApJS/122/431
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present the discovery of 60 star clusters in 20 multiband Hubble Space Telescope (HST) WFPC2 fields in M33. The fields sample a variety of environments, from outer regions to spiral arms and central regions, as well as a range of galactocentric distances. The HST spatial resolution allowed us to penetrate the crowded, spiral arm regions of M33 yielding the first unbiased, representative sample of star clusters for this galaxy. We discuss the separation of clusters from stellar sources, and from other extended sources such as star-forming regions, H II regions, and supernova remnants. For the clusters we present multiband images and discuss morphology, location, and integrated photometry. Measured cluster colors and magnitudes are presented. The cluster density in our sample as a function of galactocentric distance yields an estimate of 690 total clusters in M33.
- ID:
- ivo://CDS.VizieR/J/A+A/366/498
- Title:
- VI photometry of M33 star clusters
- Short Name:
- J/A+A/366/498
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have detected 102 star clusters in M 33, from 35 deep Hubble Space Telescope (HST) WFPC2 fields taken from our program and from the HST archive. Twenty-eight fields have V and I band imaging, and an additional seven fields are imaged in a single V filter. Eighty-two of the clusters were previously unknown. Integrated photometry reveals that 25 clusters have (V-I) colors typical of those found in Galactic globular clusters (only ten of these objects were previously known). Our discovery of 15 new globular cluster candidates increases previous estimates of the old cluster population in M 33 by ~60%. An additional eleven objects (only two were previously known) have colors expected for intermediate age clusters. The new clusters have a range of ages from 6 million years to >15Gyrs, and masses between 10^2^M_{sun}_-10^6^M_{sun}_, although these parameters are estimated from only one color.
