- ID:
- ivo://CDS.VizieR/J/ApJ/546/694
- Title:
- NICMOS star formation history
- Short Name:
- J/ApJ/546/694
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an extensive analysis of the star formation rates determined from the NICMOS deep images of the northern Hubble Deep Field. We use SED template fitting photometric techniques to determine both the redshift and the extinction for each galaxy in our field. Measurement of the individual extinctions provides a correction for star formation hidden by dust obscuration. We determine star formation rates for each galaxy based on the 1500{AA} UV flux and add the rates in redshift bins of width 1.0 centered on integer redshift values.
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- ID:
- ivo://CDS.VizieR/J/ApJ/562/303
- Title:
- Old Stellar Populations of the SMC
- Short Name:
- J/ApJ/562/303
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometry is given for six data sets of SMC photometry, all in the V and I bands. Field names in the file summary below are the names used in the STScI archive for the WFPC2 observations. WFPC2 observations of NGC 121 and the SMC fields reach limiting magnitudes of V=26 and I=25.5; ground-based observations cover a square region of 14.5 arcmin on a side and reach V=25.5 and I=24.5.
103. Orion HST survey
- ID:
- ivo://CDS.VizieR/J/AJ/111/846
- Title:
- Orion HST survey
- Short Name:
- J/AJ/111/846
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on a survey of the brightest portions of the Orion Nebula made with the Wide Field Planetary Camera 2 of the Hubble Space Telescope. Fifteen paintings were made, each employing interference filters isolating the principal emission lines of HI, [NII], and [OIII] and another isolating an interval similar to the V bandpass. A careful survey of compact objects of stellar and nearly stellar appearance was made and astrometric solutions for individual fields were used to determine positions accurate to about 0.1". 344 stars were measured, down to about V=22. In addition to structures in several of the previously known Herbig-Haro objects, 145 compact sources that can be classified as proplyds were found. Proplyds are young stars surrounded by circumstellar material which is rendered visible by being in or near an HII region. In the central region, where detection of proplyds is easiest, almost all of the low-mass pre-main-sequence stars have obvious circumstellar material. The fraction falls as one views areas away from the dominant photoionizing star {theta}^1^C Ori. Six new dark disk proplyds are found, bringing the total to seven. These are objects showing only in silhouette against the bright background of the HII region. Most of these are elliptical in form, indicating that they are circumstellar disks. In addition to these compact sources, the new images allow detection of numerous large structures previously unreported from ground-based observations. These include shells and shocks apparently related to Herbig-Haro objects and high velocity outflows from young stellar objects.
- ID:
- ivo://archive.stsci.edu/catalogs/HLSP_PHAT
- Title:
- Panchromatic Hubble Andromeda Treasury ConeSearch
- Short Name:
- PHAT CS
- Date:
- 23 Jul 2020 20:42:13
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- The Panchromatic Hubble Andromeda Treasury is a Hubble Space Telescope Multi-cycle program to map roughly a third of M31's star forming disk, using 6 filters covering from the ultraviolet through the near infrared. With HST's resolution and sensitivity, the disk of M31 will be resolved into more than 100 million stars, enabling a wide range of scientific endeavors. The PHAT observations are grouped into 23 "bricks", each listed under a different proposal ID. Each brick consists of a 3x6 array of pointings, producing complete coverage in the UV, optical, and NIR. Each brick is observed as two 3x3 "half bricks", with observations taken ~6 months apart. In the first observing season, a 3x3 half brick of WFC3 pointings is completed in primary, while parallel observations produce a highly overlapping 3x3 tile of ACS observations in the adjacent half brick. After 6 months, the telescope can be rotated by 180 degrees from the original orientation, such that the primary WFC3 pointings cover the area that was tiled by ACS in the first season, and vice versa. Each pointing is observed for 2 orbits, using the 2 WFC3 cameras for one orbit each. Filters: F275W+F336W (WFC3/UVIS), F475W+F814W (ACS/WFC), F110W+F160W (WFC3/IR) Depth: UVIS data reach a magnitude limit of ~25 in F275W and F336W. ACS data reach maximum depths of ~28 magnitudes in F475W and ~27 magnitudes in F814W in the uncrowded outer disk. In these same regions, WFC3/IR data reach maximum depths of ~26.5 and ~25.5 in F110W and F160W, respectively. However, the depth is crowding limited in the optical and NIR, and thus is a strong function of radius. As a result, photometry in the inner bulge fields is far shallower. All available catalogs are listed at http://archive.stsci.edu/vo/mast_services.html.
- ID:
- ivo://mast.stsci/phat
- Title:
- Panchromatic Hubble Andromeda Treasury (PHAT)
- Short Name:
- PHAT
- Date:
- 23 Jul 2020 19:28:22
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- The Panchromatic Hubble Andromeda Treasury is a Hubble Space Telescope Multi-cycle program to map roughly a third of M31's star forming disk, using 6 filters covering from the ultraviolet through the near infrared. With HST's resolution and sensitivity, the disk of M31 will be resolved into more than 100 million stars, enabling a wide range of scientific endeavors.
- ID:
- ivo://CDS.VizieR/J/ApJ/468/633
- Title:
- Photometry in the M31 OB association NGC 206
- Short Name:
- J/ApJ/468/633
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of our effort to determine what affects the star formation process by looking at the products of that process, we have obtained broadband Hubble Space Telescope images of the large OB association NGC 206 in the nearby spiral galaxy M31. Our images cover approximately the southern half of the association. We have detected stars down to an F555W magnitude of 25.5 and measure stars on the main sequence in NGC 206 to an M_F555W,0_ of -1 or a mass of ~6M_{sun}_. From a comparison with isochrones, ages up to about 8Myr are plausible, and we adopt an age of 6Myr. For stellar masses 6-15M_{sun}_, we determine an initial mass function slope of -1.4+/-0.5. This is close to the value for a Salpeter mass function, although the uncertainty is large. The uncertainty in the slope represents disagreement among the individual mass bins. In terms of intermediate-mass stars (6-15M_{sun}_) the NGC 206 star formation event appears to be typical of star formation processes in other nearby galaxies, and it is part of a growing number of studies ,that are finding similarities in the products of the star formation processes in a wide variety of star formation events and galactic environments. Nevertheless, the density of stars formed in NGC 206 is much lower than that in giant H II regions such as NGC 604 in M33 or 30 Doradus in the LMC and in typical OB associations.
- ID:
- ivo://CDS.VizieR/J/ApJS/122/355
- Title:
- Properties of low z QSO absorption systems
- Short Name:
- J/ApJS/122/355
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (Partial): We examine the clustering properties of low-redshift Ly{alpha} and heavy-element QSO absorption line systems seen in the spectra of 13 QSOs at the Galactic poles. This is the densest sample of ~1 degree separated QSOs observed spectroscopically with the Hubble Space Telescope to date. At the median redshift of the Ly{alpha} sample (z{=~}0.7), the QSO lines of sight are separated on transverse scales from about 15 to 200h^-1^Mpc (q_0_=0.5, H=100h.km/s/Mpc), allowing the three-dimensional clustering of the absorbers to be examined on those scales. The Galactic poles are also regions where relatively deep and wide-field galaxy redshift surveys have taken place, so the distributions of galaxies and Ly{alpha} systems can be compared within the same volume of space. There are 545 total absorption lines detected in the complete sample from 13 QSOs. We identify 307 Ly{alpha} systems, of which 18 contain heavy-element lines. We confirm the relatively slow redshift number density evolution for Ly systems at z{<=}1. There are also five likely C IV doublets in our sample, for which the Ly{alpha} line is not accessible.
- ID:
- ivo://CDS.VizieR/J/ApJ/566/993
- Title:
- rho Ophiuchus (Lynds 1688) cluster NICMOS imaging
- Short Name:
- J/ApJ/566/993
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of near-infrared photometry of young stars associated with the Ophiuchus molecular cloud based on observations made with the Hubble Space Telescope NICMOS3 camera at 1.1 and 1.6{mu}m. Our survey covers 0.02deg^2^ centered on the dense molecular cores in Lynds 1688. We detect 165 sources at 1.6{mu}m and 65 sources at 1.1{mu}m within our estimated completeness limits of 21.0 and 21.5mag, respectively.
- ID:
- ivo://CDS.VizieR/J/ApJ/480/568
- Title:
- RK photometry in 3C 336 field
- Short Name:
- J/ApJ/480/568
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present very deep WFPC2 images and FOS spectroscopy from the Hubble Space Telescope (HST) together with numerous supporting ground-based observations of the field of the quasar 3C 336 (z_em_=0.927). The observations are designed to investigate the nature of galaxies producing metal-line absorption systems in the spectrum of the QSO. Along a single line of sight, we find at least six metal-line absorption systems (of which three are newly discovered) ranging in redshift from 0.317 to 0.892. Through an extensive program of optical and IR imaging, QSO spectroscopy, and faint galaxy spectroscopy, we have identified five of the six metal-line absorption systems with luminous (L_K_>=0.1L^*^_K_) galaxies. These have morphologies ranging from very late-type spiral to S0, and they exhibit a wide range of inclination and position angles with respect to the QSO sight line. The only unidentified absorber, despite our intensive search, is a damped Lyman-{alpha} system at z_abs_=0.656. Analysis of the absorption spectrum suggests that the metal abundances ([Fe/H]=-1.2) in this system are similar to those in damped systems at z~2 and to the two other damped systems for which abundances have been determined at z<1. The absorption line system must either be associated with an underluminous, late-type spiral galaxy, which we find at a projected disk impact parameter of ~120h^-1^kpc, or with an as yet unseen, extremely faint galaxy (L<0.05L^*^_K_) near the QSO sight line that eludes detection despite our deep HST and high-resolution ground-based near-IR images. We have found no examples of intrinsically faint galaxies (L<0.1L^*^) at small impact parameters that might have been missed as absorber candidates in our previous ground-based imaging and spectroscopic programs on Mg II absorbing galaxies. We have, however, identified several intrinsically faint galaxies within ~50h^-1^kpc of the QSO sight line that do not produce detectable metal-line absorption. There are no bright galaxies (L>0.1L_K_) within 50h^-1^kpc that do not produce detectable metal lines (of Mg II {lambda}{lambda}2796, 2803 and/or C IV {lambda}{lambda}1548, 1550) in the QSO spectrum. All of these results generally support the inferences we have previously reached from a larger survey for absorption-selected galaxies at z<1. There are several other galaxies with redshifts near that of 3C 336, suggesting that the QSO is situated in an overdense region, perhaps a galaxy cluster. Previously published reports of a cluster around 3C 336 were largely misled by the presence of many foreground galaxies seen in projection near the QSO. It is possible that a reported measurement of weak shear gravitational lensing in this field may be produced by the QSO cluster itself, since there appear to be no other groups or clusters in the foreground. We find no evidence for a normal, bright QSO host galaxy, although there are several faint objects very close to the quasar and at similar redshift that might either be companions or part of a disorganized QSO host.
- ID:
- ivo://mast.stsci/siap/stages
- Title:
- Space Telescope A901/902 Galaxy Evolution Survey (STAGES)
- Short Name:
- HST.STAGES
- Date:
- 23 Jul 2020 19:41:16
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- STAGES is a large area (0.5x0.5 degree) survey of the complex Abell 901(a,b)/902 multiple-cluster system at z=0.165. An 80-tile imaging mosaic in F606W was conducted in HST cycle 13 with the HST/ACS instrument.
