- ID:
- ivo://CDS.VizieR/J/ApJ/706/158
- Title:
- Early-type galaxies in PEARS
- Short Name:
- J/ApJ/706/158
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) slitless grism spectra from the PEARS program, we study the stellar populations of morphologically selected early-type galaxies in the GOODS North and South fields. The sample - extracted from a visual classification of the (v2.0) HST/ACS images and restricted to redshifts z>0.4 - comprises 228 galaxies (i_F775W_<24mag, AB) out to z<~1.3 over 320arcmin^2^, with a median redshift z_M_=0.75. This work significantly increases our previous sample from the GRAPES survey in the HUDF (18 galaxies over ~11arcmin^2^). The grism data allow us to separate the sample into "red" and "blue" spectra, with the latter comprising 15% of the total. Three different grids of models parameterizing the star formation history are used to fit the low-resolution spectra.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/138/1022
- Title:
- Emission-line galaxies from HST PEARS survey
- Short Name:
- J/AJ/138/1022
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a search for emission-line galaxies (ELGs) in the southern fields of the Hubble Space Telescope Probing Evolution And Reionization Spectroscopically (PEARS) grism survey. The PEARS South Fields consist of five Advanced Camera for Surveys pointings (including the Hubble Ultra Deep Field) with the G800L grism for a total of 120 orbits, revealing thousands of faint object spectra in the GOODS-South region of the sky. ELGs are one subset of objects that are prevalent among the grism spectra. Using a two-dimensional detection and extraction procedure, we find 320 emission lines originating from 226 galaxy "knots" within 192 individual galaxies. Line identification results in 118 new grism-spectroscopic redshifts for galaxies in the GOODS-South Field. We measure emission-line fluxes using standard Gaussian fitting techniques. The star formation rates of the ELGs are presented, as well as a sample of distinct giant star-forming regions at z~0.1-0.5 across individual galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/772/48
- Title:
- Emission-line galaxies from PEARS. II.
- Short Name:
- J/ApJ/772/48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a full analysis of the Probing Evolution And Reionization Spectroscopically (PEARS) slitess grism spectroscopic data obtained with the Advanced Camera for Surveys on board Hubble Space Telescope. PEARS covers fields within both the Great Observatories Origins Deep Survey (GOODS) North and South fields, making it ideal as a random survey of galaxies, as well as the availability of a wide variety of ancillary observations complemented by the spectroscopic results. Using the PEARS data, we are able to identify star-forming galaxies (SFGs) within the redshift volume 0<z<1.5. Star-forming regions in the PEARS survey are pinpointed independently of the host galaxy. This method allows us to detect the presence of multiple emission-line regions (ELRs) within a single galaxy. We identified a total of 1162 H{alpha}, [OIII], and/or [OII] emission lines in the PEARS sample of 906 galaxies to a limiting flux of ~10^-18^erg/s/cm2. The ELRs have also been compared to the properties of the host galaxy, including morphology, luminosity, and mass. From this analysis, we find three key results: (1) the computed line luminosities show evidence of a flattening in the luminosity function with increasing redshift; (2) the star-forming systems show evidence of complex morphologies with star formation occurring predominantly within one effective (half-light) radius. However, the morphologies show no correlation with host stellar mass. (3) Also, the number density of SFGs with M_*_>=10^9^M_{sun}_ decreases by an order of magnitude at z<=0.5 relative to the number at 0.5<z<0.9, supporting the argument of galaxy downsizing.
- ID:
- ivo://CDS.VizieR/J/ApJ/742/111
- Title:
- Extreme emission-line galaxies in CANDELS
- Short Name:
- J/ApJ/742/111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We identify an abundant population of extreme emission-line galaxies (EELGs) at redshift z~1.7 in the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey imaging from Hubble Space Telescope/Wide Field Camera 3 (HST/WFC3). Sixty-nine EELG candidates are selected by the large contribution of exceptionally bright emission lines to their near-infrared broadband magnitudes. Supported by spectroscopic confirmation of strong [OIII] emission lines - with rest-frame equivalent widths ~1000{AA} - in the four candidates that have HST/WFC3 grism observations, we conclude that these objects are galaxies with ~10^8^M_{sun}_ in stellar mass, undergoing an enormous starburst phase with M_*_/(dM/dt)_*_ of only ~15Myr. These bursts may cause outflows that are strong enough to produce cored dark matter profiles in low-mass galaxies. The individual star formation rates and the comoving number density (3.7x10^-4^Mpc^-3^) can produce in ~4Gyr much of the stellar mass density that is presently contained in 10^8^-10^9^M_{sun}_ dwarf galaxies. Therefore, our observations provide a strong indication that many or even most of the stars in present-day dwarf galaxies formed in strong, short-lived bursts, mostly at z>1.
- ID:
- ivo://CDS.VizieR/J/AJ/130/1324
- Title:
- Faint emission-line galaxies at z<=1.6
- Short Name:
- J/AJ/130/1324
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) Grism Parallel Survey, a large program obtaining deep, slitless ACS grism (R~100) spectroscopy of high-latitude HST parallel fields. We identify 601 compact emission-line galaxies at z<=1.6, reaching emission lines to a flux limit of >~5x10^-18^ergs/cm^2^/s (3{sigma}). We determine redshifts by cross-correlation of the target spectra with template spectra, followed by visual inspection. We measure star formation rates from the observed [OII]{lambda}3727, [OIII]{lambda}5007, and H{alpha} line fluxes.
- ID:
- ivo://CDS.VizieR/J/A+A/637/A26
- Title:
- Fornax 3D project. Globular clusters
- Short Name:
- J/A+A/637/A26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Globular clusters (GCs) are found ubiquitously in massive galaxies and due to their old ages, they are regarded as fossil records of galaxy evolution. Spectroscopic studies of GC systems are often limited to the outskirts of galaxies, where GCs stand out against the galaxy background and serve as bright tracers of galaxy assembly. In this work we use the capabilities of the Multi Unit Explorer Spectrograph (MUSE) to extract a spectroscopic sample of 722 GCs in the inner regions (<3Reff) of 32 galaxies in the Fornax cluster. These galaxies were observed as part of the Fornax 3D project, a MUSE survey that targets early and late-type galaxies within the virial radius of Fornax. After accounting for the galaxy background in the GC spectra, we extracted line-of-sight velocities and determined metallicities of a subsample of 238 GCs. We found signatures of rotation within GC systems and comparing the GC kinematics and that of the stellar body shows that the angular momentum of the GC system reflects that of the stars, confirming the usefulness of GCs as kinematic tracers. While the red GCs prove to closely follow the metallicity profile of the host galaxy, the blue GCs show a large spread of metallicities but are generally more metal -poor than the host.
- ID:
- ivo://CDS.VizieR/J/ApJ/830/51
- Title:
- FourStar galaxy evolution survey (ZFOURGE)
- Short Name:
- J/ApJ/830/51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The FourStar galaxy evolution survey (ZFOURGE) is a 45 night legacy program with the FourStar near-infrared camera on Magellan and one of the most sensitive surveys to date. ZFOURGE covers a total of 400arcmin^2^ in cosmic fields CDFS, COSMOS and UDS, overlapping the CANDELS fields.
- ID:
- ivo://CDS.VizieR/J/ApJ/854/73
- Title:
- Full-data results of HFF: galaxies z~6-9
- Short Name:
- J/ApJ/854/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UV luminosity functions of dropout galaxies at z~6-10 with the complete Hubble Frontier Fields data. We obtain a catalog of ~450 dropout-galaxy candidates (350, 66, and 40 at z~6-7, 8, and 9, respectively), with UV absolute magnitudes that reach ~-14mag, ~2 mag deeper than the Hubble Ultra Deep Field detection limits. We carefully evaluate number densities of the dropout galaxies by Monte Carlo simulations, including all lensing effects such as magnification, distortion, and multiplication of images as well as detection completeness and contamination effects in a self-consistent manner. We find that UV luminosity functions at z~6-8 have steep faint-end slopes, {alpha}~-2, and likely steeper slopes, {alpha}<~-2 at z~9-10. We also find that the evolution of UV luminosity densities shows a non-accelerated decline beyond z~8 in the case of M_trunc_=-15, but an accelerated one in the case of M_trunc_=-17. We examine whether our results are consistent with the Thomson scattering optical depth from the Planck satellite and the ionized hydrogen fraction Q_HII_ at z<~7 based on the standard analytic reionization model. We find that reionization scenarios exist that consistently explain all of the observational measurements with the allowed parameters of f_esc_=0.17_-0.03_^+0.07^ and M_trunc_>-14.0 for log{xi}_ion_/[erg^-1^Hz]=25.34, where f_esc_ is the escape fraction, Mtrunc is the faint limit of the UV luminosity function, and {xi}_ion_ is the conversion factor of the UV luminosity to the ionizing photon emission rate. The length of the reionization period is estimated to be {Delta}z=3.9_-1.6_^+2.0^ (for 0.1<Q_HII_<0.99), consistent with the recent estimate from Planck.
- ID:
- ivo://CDS.VizieR/J/ApJ/625/156
- Title:
- FUV-NUV observations of NGC 2808
- Short Name:
- J/ApJ/625/156
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a reanalysis of far-ultraviolet (FUV) observations of the globular cluster NGC 2808 obtained with the Hubble Space Telescope. These data were first analyzed by Brown and coworkers (2001, Cat. <J/ApJ/562/368>), with an emphasis on the bright, blue horizontal-branch (HB) stars in this cluster. Here, our focus is on the population of fainter FUV sources, which include white dwarfs (WDs), blue stragglers (BSs), and cataclysmic variables (CVs).
- ID:
- ivo://CDS.VizieR/J/AJ/133/504
- Title:
- Galaxies around CenA/M83 galaxy complex
- Short Name:
- J/AJ/133/504
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Hubble Space Telescope ACS images and color-magnitude diagrams for 24 nearby galaxies in and near the constellation of Centaurus with radial velocities V_LG_<550km/s. Distances are determined based on the luminosities of stars at the tip of the red giant branch that range from 3.0 to 6.5Mpc. The galaxies are concentrated in two spatially separated groups around Cen A (NGC 5128) and M83 (NGC 5236).
