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Start Over Subject infrared photometry Facility HST
11. IR Observations in HDF-North
ID:
ivo://CDS.VizieR/J/ApJ/596/748
Title:
IR Observations in HDF-North
Short Name:
J/ApJ/596/748
Date:
21 Oct 2021
Publisher:
CDS
Description:
The original analysis of the star formation history in the NICMOS deep images of the northern Hubble Deep Field (NHDF) is extended to the entire NHDF utilizing NICMOS and WFPC2 archival data. The roughly constant star formation rate from redshifts 16 found in this study is consistent with the original results. Star formation rates from this study, Lyman break galaxies, and submillimeter observations are now in concordance. The spike of star formation at redshift 2 due to two ultraluminous IR galaxies in the small deep NICMOS field is smoothed out in the larger area results presented here. The larger source base of this study allows comparison with predictions from hierarchical galaxy formation models. In general, the observation are consistent with the predictions. The observed luminosity functions at redshifts 16 are presented for future comparisons with theoretical galaxy evolution calculations. Mid- and far-infrared properties of the sources are also calculated and compared with observations. A candidate for the VLA source VLA 3651+1221 is discussed.
12. 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.
13. 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.
14. rho Ophiuchus (Lynds 1688) cluster NICMOS imaging
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.
15. VI photometry of M33 star clusters
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.
16. VI photometry of NGC 2157
ID:
ivo://CDS.VizieR/J/AJ/115/592
Title:
VI photometry of NGC 2157
Short Name:
J/AJ/115/592
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have carried out Wide Field Planetary Camera 2 V- and I-band imaging of the young LMC cluster NGC 2157. Construction of a color-magnitude diagram and isochrone fitting yield an age of {tau}=10^8^yr, a reddening E(B-V)=0.1, and a distance modulus of 18.4mag. Our data cover the mass range 0.75M_{sun}_<=m<=5.1M_{sun}_. We find that the cluster mass function changes significantly from the inner regions to the outer regions, becoming steeper (larger number of low-mass stars relative to high-mass stars) at larger radii. The age of NGC 2157 is comparable to its two-body relaxation timescale only in the cluster core. The observed steepening of the mass function at larger radii is therefore most likely an initial condition of the cluster stars. Such initial conditions are predicted in models of cluster star formation in which dissipative processes act more strongly upon more massive stars.

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