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41. HST FOS spectral atlas
ID:
ivo://CDS.VizieR/J/ApJS/140/143
Title:
HST FOS spectral atlas
Short Name:
J/ApJS/140/143
Date:
21 Oct 2021
Publisher:
CDS
Description:
We analyzed the absorption line spectra of all quasars observed with the high-resolution gratings of the Faint Object Spectrograph on board the Hubble Space Telescope. We examined 788 spectra for 334 quasars and present line lists and identifications of absorption lines in the spectra of 271 of them. Analysis of the statistics of the Ly{alpha} and metal absorption systems are presented in companion papers. The data and several analysis products are available on the authors' Web site, http://lithops.as.arizona.edu/~jill/QuasarSpectra .
42. HST Galaxy Evolution from Morphology and SEDs
ID:
ivo://mast.stsci/siap/hst.gems
Title:
HST Galaxy Evolution from Morphology and SEDs
Short Name:
HST.GEMS
Date:
22 Jul 2020 22:30:27
Publisher:
Space Telescope Science Institute Archive
Description:
GEMs is a large-area (800 arcmin 2) two-color (F606W and F850LP) imaging survey with the Advanced Camera for Surveys on the Hubble Space Telescope. Centered on the Chandra Deep Field-South, it covers an area of ~ 28'x28', or about 120 HDF areas, to a depth of MAB(F606W)=28.5(5s) for compact sources. Focusing on the redshift range ~ 0.2<z<1.1, GEMS provides morphologies and structural parameters for nearly 10,000 galaxies where redshift estimates, luminosities, and SEDs exist from COMBO-17.
43. HST Hubble Deep Field
ID:
ivo://mast.stsci/siap/hst.hdf
Title:
HST Hubble Deep Field
Short Name:
HST.HDF
Date:
23 Jul 2020 19:35:54
Publisher:
Space Telescope Science Institute Archive
Description:
The Hubble Deep Field (HDF) is a Director's Discretionary program on HST in Cycle 5 to image a typical field at high galactic latitude in four wavelength passbands as deeply as reasonably possible. In order to optimize observing in the time available, a field in the northern continuous viewing zone (CVZ) was selected and images were taken for 10 consecutive days, or approximately 150 orbits. Shorter 1-orbit images were also obtained of the fields immediately adjacent to the primary HDF in order to facilitate spectroscopic follow-up by ground-based telescopes. The observations were carried out from 18-30 December 1995, and the data are available to the community for study.
44. HST Hubble Deep Field South
ID:
ivo://mast.stsci/siap/hst.hdf_south
Title:
HST Hubble Deep Field South
Short Name:
HST.HDF_SOUTH
Date:
23 Jul 2020 19:36:18
Publisher:
Space Telescope Science Institute Archive
Description:
A second Hubble Deep Field campaign was carried out between late September and October of 1998. The raw, pipeline calibrated and reprocessed data were released to the community on November 23, 1998. The rationale for undertaking a second deep field campaign followed from the wealth of information that has come out of HDF-N, and from the desire to provide a point of focus for similar studies of the distant universe from southern-hemisphere facilities. Simultaneous, parallel observations were made with the three HST instruments STIS, WFPC2 and NICMOS of separate, neighboring fields. As was the case for HDF-N, approximately 150 consecutive orbits were devoted to a single telescope pointing.
45. HST Hubble HELIX Observations
ID:
ivo://mast.stsci/siap/hst.helix
Title:
HST Hubble HELIX Observations
Short Name:
HST.HELIX
Date:
22 Jul 2020 22:22:06
Publisher:
Space Telescope Science Institute Archive
Description:
For the 14 hours of peak Leonid meteoroid flux in November 2002, the Hubble Space Telescope was pointed away from the radiant, and the solar arrays were oriented to minimize their cross-section. By coincidence, one of the nearest and largest planetary nebulae, the Helix Nebula (NGC 7293), was nearly opposite the incoming Leonids and could be observed. A "Hubble Helix Team" (below) of volunteers led by Margaret Meixner (STScI) organized a nine-orbit campaign to observe the Helix with the ACS, WFPC2, NICMOS, and STIS.
46. HST observations of carbon in spiral galaxies
ID:
ivo://CDS.VizieR/J/ApJ/513/168
Title:
HST observations of carbon in spiral galaxies
Short Name:
J/ApJ/513/168
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present measurements of the gas-phase abundance ratio C/O in six H II regions in the spiral galaxies M101 and NGC 2403, based on ultraviolet spectroscopy using the Faint Object Spectrograph on the Hubble Space Telescope. The ratios of C to O increase systematically with O/H in both galaxies, from log(C/O){~=}-0.8 at log(O/H){~=}-4.0 to log(C/O){~=}-0.1 at log(O/H){~=}-3.4. C/N shows no correlation with O/H. The rate of increase of C/O is somewhat uncertain because of uncertainty as to the appropriate UV reddening law and uncertainty in the metallicity dependence on grain depletions. However, the trend of increasing C/O with O/H is clear, confirming and extending the trend in C/O indicated previously from observations of irregular galaxies. Our data indicate that the radial gradients in C/H across spiral galaxies are steeper than the gradients in O/H. Comparing the data to chemical-evolution models for spiral galaxies shows that models in which the massive star yields do not vary with metallicity predict radial C/O gradients that are much flatter than the observed gradients.
47. HST observations of clusters in NGC 3597
ID:
ivo://CDS.VizieR/J/AJ/117/1700
Title:
HST observations of clusters in NGC 3597
Short Name:
J/AJ/117/1700
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have analyzed HST/WFPC2 images of NGC 3597 and find {=~}700 compact objects surrounding the galaxy with an average (B-R)_0_ {=~}0.6. We propose that the majority of these objects are young globular clusters. They have a spread in colors that is consistent with that expected for a population of young clusters with a common age and spread induced by photometric errors and reddening within NGC 3597.
48. HST observations of low-mass stars in IC 348
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.
49. HST observations of old clusters in the LMC
ID:
ivo://CDS.VizieR/J/ApJ/527/199
Title:
HST observations of old clusters in the LMC
Short Name:
J/ApJ/527/199
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present V, V-I color-magnitude diagrams (CMDs) for three old star clusters in the Large Magellanic Cloud (LMC): NGC 1466, NGC 2257, and Hodge 11. Our data extend {~}3 mag below the main-sequence turnoff, allowing us to determine accurate relative ages and the blue straggler frequencies. Based on a differential comparison of the CMDs, any age difference between the three LMC clusters is less than 1.5 Gyr. Comparing their CMDs to those of M92 and M3, the LMC clusters, unless their published metallicities are significantly in error, are the same age as the old Galactic globulars. The similar ages to Galactic globulars are shown to be consistent with hierarchical clustering models of galaxy formation. The blue straggler frequencies are also similar to those of Galactic globular clusters. We derive a true distance modulus to the LMC of (m - M)_0_ = 18.46 {+/-} 0.09 [assuming (m - M)_0_ = 14.61 for M92] using these three LMC clusters.
50. HST Observations of SMC N88A
ID:
ivo://CDS.VizieR/J/A+A/347/841
Title:
HST Observations of SMC N88A
Short Name:
J/A+A/347/841
Date:
21 Oct 2021
Publisher:
CDS
Description:
High-resolution Hubble Space Telescope images have allowed us for the first time to resolve the compact SMC ionized ``blob'' N88A (diameter ~3.5arcsec or 1pc). This very young HII, region, which is hatching from its natal molecular cloud, is heavily affected by absorbing dust associated with the cloud. The interstellar reddening towards N88A is on average A_v_~1.5mag and strikingly rises to more than 3.5mag in a narrow dust band crossing the core of the HII region. Such a high extinction is unprecedented for an HII region in the metal-poor SMC. We present the photometry of some 70 stars lying towards the OB association at the center of which lies N88A. The exciting star(s) of N88A is not detected, due to the heavy extinction. The chronology of star formation is discussed for the whole region.