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- ID:
- ivo://CDS.VizieR/J/ApJ/551/111
- Title:
- HDF early-type and spiral galaxies
- Short Name:
- J/ApJ/551/111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze the internal optical colors of a complete sample of I_814_<24mag early-type and spiral galaxies from the northern and southern Hubble Deep Fields (HDF). The subset of galaxies in the HDF-North are also investigated in the near-infrared using NICMOS photometry. We compare the central (inner 5% radius) colors of those spirals with clearly visible bulges with the integrated colors of ellipticals in our sample.
- 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.
- 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/ApJ/538/493
- Title:
- HDF-South NICMOS field
- Short Name:
- J/ApJ/538/493
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of photometry and photometric redshifts of 335 faint objects in the Hubble Deep Field South (HDF-S) near-infrared camera and multiobject spectrograph (NICMOS) field. The analysis is based on (1) infrared images obtained with the Hubble Space Telescope (HST) using the NICMOS with the F110W, F160W, and F222M filters; (2) an optical image obtained with HST using the Space Telescope Imaging Spectrograph with no filter; and (3) optical images obtained with the European Southern Observatory Very Large Telescope with U, B, V, R, and I filters. The primary utility of the catalog of photometric redshifts is as a survey of faint galaxies detected in the NICMOS F160W and F222M images. The sensitivity of the survey varies significantly with position, reaching a limiting depth of AB(1.6{mu}m)~28.7 and covering 1.01arcmin^2^ to AB(1.6{mu}m)=27 and 1.05arcmin^2^ to AB(1.6{mu}m)=26.5. The catalog of photometric redshifts identifies 21 galaxies (or 6% of the total) of redshift z>5, eight galaxies (or 2% of the total) of redshift z>10, and 11 galaxies (or 3% of the total) of best-fit spectral type E/S0, of which five galaxies (or 1% of the total) are of redshift z>1.
- 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/ApJ/541/977
- Title:
- HST observations of low-mass stars in IC 348
- Short Name:
- J/ApJ/541/977
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the low-mass population of the young cluster IC 348 down to the deuterium-burning limit, a fiducial boundary between brown dwarf and planetary mass objects, using a new and innovative method for the spectral classification of late-type objects. Using photometric indices, constructed from HST/NICMOS narrowband imaging, that measure the strength of the 1.9{mu}m water band, we determine the spectral type and reddening for every M-type star in the field, thereby separating cluster members from the interloper population. Due to the efficiency of our spectral classification technique, our study is complete from ~0.7 to 0.015M_{sun}_. The mass function derived for the cluster in this interval, dN/dlogM{prop.to}M^0.5^, is similar to that obtained for the Pleiades, but appears significantly more abundant in brown dwarfs than the mass function for companions to nearby Sunlike stars. This provides compelling observational evidence for different formation and evolutionary histories for substellar objects formed in isolation versus as companions. Because our determination of the IMF is complete to very low masses, we can place interesting constraints on the role of physical processes such as fragmentation in the star and planet formation process and the fraction of dark matter in the Galactic halo that resides in substellar objects.
- 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/AJ/116/2081
- Title:
- Hubble Deep Field catalog of color-based redshift
- Short Name:
- J/AJ/116/2081
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive simple empirical color-redshift relations for z<~4 galaxies in the Hubble Deep Field (HDF) using a linear function of three photometric colors (U-B, B-V, V-I). The dispersion between the estimated redshifts and the spectroscopically observed ones is small for relations derived in several separate color regimes; the dispersions range from {sigma}_z_~=0.03 to 0.1 for z<~2 galaxies, and from {sigma}_z_~=0.14 to 0.25 for z>~2 galaxies. We apply the color-redshift relations to the HDF photometric catalog and obtain estimated redshifts that are consistent with those derived from spectral template fitting methods. The advantage of these color-redshift relations is that they are simple and easy to use and do not depend on the assumption of any particular spectral templates; they provide model independent redshift estimates for z<~4 galaxies using only multiband photometry, and they apply to about 90% of all galaxies. We provide a color-based estimated redshift catalog of HDF galaxies to z<~4. We use the estimated redshifts to investigate the redshift distribution of galaxies in the HDF; we find peaks in the redshift distribution that suggest large-scale clustering of galaxies to at least z~1 and that are consistent with those identified in spectroscopic probes of the HDF.
- ID:
- ivo://CDS.VizieR/J/AJ/117/17
- Title:
- Hubble Deep Field near-IR obs.
- Short Name:
- J/AJ/117/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents data obtained during the NICMOS Guaranteed Time Observations of a portion of the Hubble Deep Field. The data are in a catalog format similar to the publication of the original WFPC2 Hubble Deep Field program (Williams et al., 1996, Cat. <J/AJ/112/1335>). The catalog contains 342 objects in a 49.1"x48.4" subfield of the total observed field, 235 of which are considered coincident with objects in the WFPC2 catalog. The 3{sigma} signal-to-noise ratio level is at an aperture AB magnitude of approximately 28.8 at 1.6{mu}m. The catalog sources, listed in order of right ascension, are selected to satisfy a limiting signal-to-noise ratio criterion of greater than or equal to 2.5. This introduces a few false detections into the catalog, and users should take careful note of the completeness and reliability levels for the catalog discussed in sections 9 and 10. The catalog also contains a test parameter indicating the results of half-catalog tests and the degree of coincidence with the original WFPC2 catalog.
