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41. Multicolor photometry in NGC 1512 and NGC 5248
ID:
ivo://CDS.VizieR/J/AJ/121/3048
Title:
Multicolor photometry in NGC 1512 and NGC 5248
Short Name:
J/AJ/121/3048
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present broadband (U, V, I, and H) and narrowband (H{alpha}+[N II] and Pa{alpha}) images of the circumnuclear starburst rings in two nearby spiral galaxies, NGC 1512 and NGC 5248, obtained with the WFPC2 and NICMOS cameras on HST. Combined with previously published ultraviolet (UV) HST images at 2300{AA} these data provide a particularly wide wavelength range with which to study the properties of the stellar populations, the gas, and the dust in the rings.
42. Near Infrared Camera and Multi Object Spectrograph
ID:
ivo://archive.stsci.edu/hst/nicmos
Title:
Near Infrared Camera and Multi Object Spectrograph
Short Name:
HST.NICMOS
Date:
23 Jul 2020 19:50:23
Publisher:
Space Telescope Science Institute Archive
Description:
The HST Near Infrared Camera and Multi-Object Spectrometer (NICMOS) provides imaging capabilities in broad, medium, and narrow band filters, broad-band imaging polarimetry, coronographic imaging, and slitless grism spectroscopy, in the wavelength range 0.8-2.5 microns. NICMOS has three adjacent but not contiguous cameras, designed to operate independently, each with a dedicated array at a different magnification scale.
43. NICMOS star formation history
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.
44. Space Telescope Imaging Spectrograph
ID:
ivo://archive.stsci.edu/hst/stis
Title:
Space Telescope Imaging Spectrograph
Short Name:
HST.STIS
Date:
23 Jul 2020 19:50:49
Publisher:
Space Telescope Science Institute Archive
Description:
The Space Telescope Imaging Spectrograph (STIS) was installed in HST on Feb. 14, 1997, replacing the GHRS spectrograph. STIS provides spectra and images at ultraviolet and visible wavelengths, probing the Universe from our solar system out to cosmological distances.
45. Star Clusters in M33
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.
46. STIS emission-line galaxies observations
ID:
ivo://CDS.VizieR/J/ApJS/146/209
Title:
STIS emission-line galaxies observations
Short Name:
J/ApJS/146/209
Date:
21 Oct 2021
Publisher:
CDS
Description:
In the first 3 years of operation the Space Telescope Imaging Spectrograph (STIS) obtained slitless spectra of ~2500 fields in parallel to prime Hubble Space Telescope (HST) observations as part of the STIS parallel survey (SPS). The archive contains ~300 fields at high Galactic latitude (|b|>30{deg}) with spectroscopic exposure times greater than 3000s. This sample contains 219 fields (excluding special regions and requiring a consistent grating angle) observed between 1997 June 6 and 2000 September 21, with a total survey area of ~160-arcmin^2^. At this depth, the SPS detects an average of one emission-line galaxy per three fields. We present the analysis of these data and the identification of 131 low- to intermediate-redshift galaxies detected by optical emission lines. The sample contains 78 objects with emission lines that we infer to be redshifted [O II] {lambda}3727 emission at 0.43<z<1.7. The comoving number density of these objects is comparable to that of H{alpha}-emitting galaxies in the NICMOS parallel observations. One quasar and three probable Seyfert galaxies are detected. Many of the emission-line objects show morphologies suggestive of mergers or interactions. The reduced data are available upon request from the authors.
47. The Carina Dwarf
ID:
ivo://CDS.VizieR/J/AJ/114/1458
Title:
The Carina Dwarf
Short Name:
J/AJ/114/1458
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present our analysis of Hubble Space Telescope Wide Field Planetary Camera 2 observations in F555W (~V) and F814W (~I) of the Carina dwarf spheroidal galaxy. The resulting V vs V-I color-magnitude diagrams reach V~27.1mag. The reddening of Carina is estimated to be E(V-I)=0.08+/-0.02 mag. A new estimate of the distance modulus of Carina, (m-M)0=19.87+/-0.11mag, has been derived primarily from existing photometry in the literature. The apparent distance moduli in V and I were determined to be (m-M)V=20.05+/-0.11mag and (m-M)I=19.98+/-0.12mag, respectively. These determinations assumed that Carina has a metallicity of [Fe/H]=-1.9+/-0.2dex. This space-based observation, when combined with previous ground-based observations, is consistent with (but does not necessarily prove) the following star formation scenario. The Carina dwarf spheroidal galaxy formed its old stellar population in a short burst (<~3Gyr) at about the same time the Milky Way formed its globular clusters. The dominant burst of intermediate-age star formation then began in the central region of the galaxy where stars formed for several billion years before the process of star formation became efficient enough in the outer regions of the galaxy to allow for the formation of large numbers of stars. There has been negligible star formation during the last few billion years. This observation provides evidence that at least some dwarf galaxies can have complex global star formation histories with local variations of the rate of star formation as a function of time and position within the galaxy. (c) 1997 American Astronomical Society.
48. UGC 6456 HST photometry
ID:
ivo://CDS.VizieR/J/AJ/116/146
Title:
UGC 6456 HST photometry
Short Name:
J/AJ/116/146
Date:
21 Oct 2021
Publisher:
CDS
Description:
Photometry on the UVI system has been performed on the resolved stellar content of the blue compact dwarf galaxy UGC 6456 using Wide Field Planetary Camera 2 (WFPC2) images obtained with the Hubble Space Telescope. The resulting color-magnitude diagram (CMD) goes to about V=27.5 and reveals not only a young population of blue main-sequence stars and blue and red supergiants, but also an older evolved population of red giants and a fairly well represented asymptotic giant branch. The distance to the galaxy is estimated from the tip of the red giant branch to be 4.5Mpc, placing it about 1.5Mpc farther away than the major members of the M81 Group, with which it is usually associated. The youngest stars are generally associated with H ii regions shown on our Halpha image and are largely confined to the 745pc field of our PC images. A comparison of their distribution in the CMD with theoretical isochrones suggests ages from 4 to 10Myr. The population of older stars is found throughout all WFPC2 camera fields and seems to show an elliptical distribution with an aspect ratio of about 2.4 and an exponential falloff in surface density with distance from a center of symmetry that is not far from the centroid of the youngest stars. Theoretical modeling of the CMD at a metallicity of Z=0.001 suggests star formation in the age interval 1-2Gyr, a strong burst in the interval 600-800Myr, and a lower rate of star formation up to the present. The evidence is compatible with a scenario beginning with the formation of a population of low-metallicity stars, enriching a major residual of prestellar material that subsequently fueled an active episode of star formation. That burst of star formation must have been particularly spectacular and may be related to the activity we now see in the distant blue dwarf galaxies revealed in deep imaging.
49. UV Images of Nearby Galaxies
ID:
ivo://CDS.VizieR/J/ApJS/107/215
Title:
UV Images of Nearby Galaxies
Short Name:
J/ApJS/107/215
Date:
21 Oct 2021
Publisher:
CDS
Description:
The accompanying tables are part of a pictorial atlas of UV (2300A) images, obtained with the Hubble Space Telescope (HST) Faint Object Camera, of the central 22"x22" of 110 galaxies. The observed galaxies are an unbiased selection constituting about one half of a complete sample of all large (D>6') and nearby (V< 2000 km/s) galaxies. This is the first extensive UV imaging survey of normal galaxies. The data are useful for studying star formation, low-level nuclear activity, and UV emission by evolved stellar populations in galaxies. At the HST resolution (0.05"), the images display an assortment of morphologies and UV brightnesses. These include bright nuclear point sources, compact young star clusters scattered in the field or arranged in circumnuclear rings, centrally-peaked diffuse light distributions, and galaxies with weak or undetected UV emission. We measure the integrated 2300A flux in each image, and classify the UV morphology. The UV and optical parameters are given in the tables.
50. VI photometry of HST faint field galaxies
ID:
ivo://CDS.VizieR/J/ApJ/453/48
Title:
VI photometry of HST faint field galaxies
Short Name:
J/ApJ/453/48
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a complete morphologically classified sample of 144 faint field galaxies from the HST Medium Deep Survey with 20.0=<Imag<22.0mag. We compare the global properties of the ellipticals and early- and late-type spirals and find a non-negligible fraction (13/144) of compact blue [(V-I)<1.0mag] systems with r^1/4^ profiles. We give the differential galaxy number counts for ellipticals and early-type spirals independently and find that the data are consistent with no-evolution predictions based on conventional flat Schechter luminosity functions (LFs) and a standard cosmology. Conversely, late-type/irregulars show a steeply rising differential number count with slope ({delta}logN/{delta}m)=0.64+/-0.1. No-evolution models based on the Loveday et al. (1992ApJ...390..338L) and Marzke et al. (1994AJ....108..437M & 1994ApJ...428...43M) local luminosity functions underpredict the late-type/irregular counts by 1.0 and 0.5dex, respectively, at Imag=21.75mag. Examination of the irregulars alone shows that ~50% appear inert and the remainder have multiple cores. If the inert galaxies represent a non-evolving late-type population, then a Loveday-like LF ({alpha}=~-1.0) is ruled out for these types, and an LF with a steep faint end ({alpha}=~-1.5) is suggested. If multiple core structure indicates recent star formation, then the observed excess of faint blue field galaxies is likely a result of et evolutionary processes acting on a steep field LF for late-type/irregulars. The evolutionary mechanism is unclear, but 60% of the multiple-core irregulars show close companions. To reconcile a Marzke-like LF with the faint redshift surveys, this evolution must be preferentially occurring in the brightest late-type galaxies with z>=0.5 at m_I_=21.75mag.