- ID:
- ivo://CDS.VizieR/J/ApJ/586/765
- Title:
- HST K-selected extremely red galaxies
- Short Name:
- J/ApJ/586/765
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We selected 115 extremely red objects (EROs) from deep Hubble Space Telescope (HST) WFPC2 archive data combined with ground-based K-band images, with (F814W-Ks)>=4, K-band signal-to-noise ratio >=5, and a median limiting Ks magnitude of ~18.7, over a corresponding area of 228 arcmin2, for a morphological study of the ERO galaxy population. The survey covered a total of ~409-arcmin^2^ over 77 separate WFPC2 fields. This is the first complete sample of bright EROs with high-resolution HST morphologies.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/417/114
- Title:
- HST/NICMOS Galactic Center survey catalogue
- Short Name:
- J/MNRAS/417/114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our Hubble Space Telescope/Near-Infrared Camera and Multi-Object Spectrometer (HST/NICMOS) Paschen {alpha} survey of the Galactic Centre, first introduced by Wang et al. (2010MNRAS.402..895W), provides a uniform, panoramic, high-resolution map of stars and an ionized diffuse gas in the central 416arcmin^2^ of the Galaxy. This survey was carried out with 144 HST orbits using two narrow-band filters at 1.87 and 1.90um in NICMOS Camera 3. In this paper, we describe in detail the data reduction and mosaicking procedures followed, including background level matching and astrometric corrections. We have detected ~570000 near-infrared (near-IR) sources using the 'starfinder' software and are able to quantify photometric uncertainties of the detections.
- ID:
- ivo://CDS.VizieR/J/ApJ/730/125
- Title:
- HST/NICMOS observations of bright IR galaxies
- Short Name:
- J/ApJ/730/125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new results on the physical nature of infrared-luminous sources at 0.5<z<2.8 as revealed by HST/NICMOS imaging and Infrared Spectrograph mid-infrared spectroscopy. Our sample consists of 134 galaxies selected at 24um with a flux of S(24um)>0.9mJy. We find many (~60%) of our sources to possess an important bulge and/or central point source component, most of which reveal additional underlying structures after subtraction of a best-fit Sersic (or Sersic+PSF) profile. Based on visual inspection of the NIC2 images and their residuals, we estimate that ~80% of all our sources are mergers. We calculate lower and upper limits on the merger fraction to be 62% and 91%, respectively. At z<1.5, we observe objects in early (pre-coalescence) merging stages to be mostly disk and star formation dominated, while we find mergers to be mainly bulge dominated and active galactic nucleus (AGN)-starburst composites during coalescence and then AGN dominated in late stages. This is analogous to what is observed in local ULIRGs. Finally, we observe obscured ({tau}_9.7um_>3.36) quasars to live in faint and compact hosts and show that these are likely high-redshift analogs of local dense-core mergers. We find late-stage mergers to possess predominantly unobscured AGN spectra, but do not observe other morphological classes to carry any specific combination of {tau}_9.7um_ and polycyclic aromatic hydrocarbon (PAH) equivalent width.
- ID:
- ivo://CDS.VizieR/J/ApJ/876/85
- Title:
- HST observations for LMC Cepheids
- Short Name:
- J/ApJ/876/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an improved determination of the Hubble constant from Hubble Space Telescope (HST) observations of 70 long-period Cepheids in the Large Magellanic Cloud (LMC). These were obtained with the same WFC3 photometric system used to measure extragalactic Cepheids in the hosts of SNe Ia. Gyroscopic control of HST was employed to reduce overheads while collecting a large sample of widely separated Cepheids. The Cepheid period-luminosity relation provides a zero-point-independent link with 0.4% precision between the new 1.2% geometric distance to the LMC from detached eclipsing binaries (DEBs) measured by Pietrzynski+ (2019Natur.567..200P) and the luminosity of SNe Ia. Measurements and analysis of the LMC Cepheids were completed prior to knowledge of the new DEB LMC distance. Combined with a refined calibration of the count-rate linearity of WFC3-IR with 0.1% precision, these three improved elements together reduce the overall uncertainty in the geometric calibration of the Cepheid distance ladder based on the LMC from 2.5% to 1.3%. Using only the LMC DEBs to calibrate the ladder, we find H_0_=74.22+/-1.82km/s/Mpc including systematic uncertainties, 3% higher than before for this particular anchor. Combining the LMC DEBs, masers in NGC 4258, and Milky Way parallaxes yields our best estimate: H_0_=74.03+/-1.42km/s/Mpc, including systematics, an uncertainty of 1.91%-15% lower than our best previous result. Removing any one of these anchors changes H0 by less than 0.7%. The difference between H0 measured locally and the value inferred from Planck CMB and {Lambda}CDM is 6.6+/-1.5km/s/Mpc or 4.4{sigma} (P=99.999% for Gaussian errors) in significance, raising the discrepancy beyond a plausible level of chance. We summarize independent tests showing that this discrepancy is not attributable to an error in any one source or measurement, increasing the odds that it results from a cosmological feature beyond {Lambda}CDM.
- ID:
- ivo://CDS.VizieR/J/ApJ/746/88
- Title:
- HST observations of GCs in NGC 1399
- Short Name:
- J/ApJ/746/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We combine new Wide Field Camera 3 IR Channel (WFC3/IR) F160W (H_160_) imaging data for NGC 1399, the central galaxy in the Fornax cluster, with archival F475W (g_475_), F606W (V_606_), F814W (I_814_), and F850LP (z _850_) optical data from the Advanced Camera for Surveys (ACS). The purely optical g_475_-I_814_, V_606_-I_814_, and g_475_-z_850_colors of NGC 1399's rich globular cluster (GC) system exhibit clear bimodality, at least for magnitudes I_814_>21.5. The optical-IR I_814_-H_160_ color distribution appears unimodal, and this impression is confirmed by mixture modeling analysis. The V_606_-H_160_ colors show marginal evidence for bimodality, consistent with bimodality in V_606_-I_814_ and unimodality in I_814_-H_160_.
- ID:
- ivo://CDS.VizieR/J/AJ/143/16
- Title:
- HST photometry of IC 883 star clusters
- Short Name:
- J/AJ/143/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New optical Hubble Space Telescope (HST), Spitzer Space Telescope, Galaxy Evolution Explorer, and Chandra observations of the single-nucleus, Luminous InfraRed Galaxy (LIRG) merger IC 883 are presented. The galaxy is a member of the Great Observatories All-sky LIRG Survey (GOALS) and is of particular interest for a detailed examination of a luminous late-stage merger due to the richness of the optically visible star clusters and the extended nature of the nuclear X-ray, mid-IR, CO, and radio emission. In the HST Advanced Camera for Surveys images, the galaxy is shown to contain 156 optically visible star clusters distributed throughout the nuclear regions and tidal tails of the merger, with a majority of visible clusters residing in an arc ~3-7kpc from the position of the mid-infrared core of the galaxy. The luminosity functions of the clusters have an {alpha}_F435W_~-2.17 +/-0.22 and {alpha}_F814W_~-2.01+/-0.21, compared with V-band-derived values measured for the well-studied LIRG NGC 34 and the Antennae Galaxy of {alpha}~-1.7+/-0.1 and -2.13+/-0.07, respectively.
- ID:
- ivo://CDS.VizieR/J/AJ/141/14
- Title:
- HST WFC3 ERS : emission-line galaxies
- Short Name:
- J/AJ/141/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present grism spectra of emission-line galaxies (ELGs) from 0.6 to 1.6um from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope. These new infrared grism data augment previous optical Advanced Camera for Surveys G800L 0.6-0.95um grism data in GOODS-South from the PEARS program, extending the wavelength coverage well past the G800L red cutoff. The Early Release Science (ERS) grism field was observed at a depth of two orbits per grism, yielding spectra of hundreds of faint objects, a subset of which is presented here. ELGs are studied via the H{alpha}, [OIII], and [OII] emission lines detected in the redshift ranges 0.2~<z~<1.4, 1.2~<z~<2.2, and 2.0~<z~<3.3, respectively, in the G102 (0.8-1.1um; R~=210) and G141 (1.1-1.6um; R~=130) grisms.
- ID:
- ivo://CDS.VizieR/J/ApJ/730/119
- Title:
- HST/WFC3 observations of Cepheids in SN Ia hosts
- Short Name:
- J/ApJ/730/119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) to determine the Hubble constant from optical and infrared observations of over 600 Cepheid variables in the host galaxies of eight recent Type Ia supernovae (SNe Ia), providing the calibration for a magnitude-redshift relation based on 253 SNe Ia.
- ID:
- ivo://CDS.VizieR/J/ApJ/800/18
- Title:
- HST/WFC3 observations of z~7-8 galaxies in A2744
- Short Name:
- J/ApJ/800/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Exploiting the power of gravitational lensing, the Hubble Frontier Fields (HFF) program aims at observing six massive galaxy clusters to explore the distant universe far beyond the limits of blank field surveys. Using the complete Hubble Space Telescope observations of the first HFF cluster A2744, we report the detection of 50 galaxy candidates at z~7 and eight candidates at z~8 in a total survey area of 0.96arcmin^2^ in the source plane. Three of these galaxies are multiply imaged by the lensing cluster. Using an updated model of the mass distribution in the cluster we were able to calculate the magnification factor and the effective survey volume for each galaxy in order to compute the ultraviolet galaxy luminosity function (LF) at both redshifts 7 and 8. Our new measurements reliably extend the z~7 UV LF down to an absolute magnitude of M_UV_~-15.5. We find a characteristic magnitude of M_UV_^*^=-20.90_-0.73_^+0.90^mag and a faint-end slope {alpha}=-2.01_-0.28_^+0.20^, close to previous determinations in blank fields. We show here for the first time that this slope remains steep down to very faint luminosities of 0.01L^*^. Although prone to large uncertainties, our results at z~8 also seem to confirm a steep faint-end slope below 0.1L^*^. The HFF program is therefore providing an extremely efficient way to study the faintest galaxy populations at z>7 that would otherwise be inaccessible with current instrumentation. The full sample of six galaxy clusters will provide even better constraints on the buildup of galaxies at early epochs and their contribution to cosmic reionization.
- ID:
- ivo://CDS.VizieR/J/ApJ/826/56
- Title:
- HST/WFC3 obs. of Cepheids in SN Ia host gal.
- Short Name:
- J/ApJ/826/56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) to reduce the uncertainty in the local value of the Hubble constant from 3.3% to 2.4%. The bulk of this improvement comes from new near-infrared (NIR) observations of Cepheid variables in 11 host galaxies of recent type Ia supernovae (SNe Ia), more than doubling the sample of reliable SNe Ia having a Cepheid-calibrated distance to a total of 19; these in turn leverage the magnitude-redshift relation based on ~300 SNe Ia at z<0.15. All 19 hosts as well as the megamaser system NGC 4258 have been observed with WFC3 in the optical and NIR, thus nullifying cross-instrument zeropoint errors in the relative distance estimates from Cepheids. Other noteworthy improvements include a 33% reduction in the systematic uncertainty in the maser distance to NGC 4258, a larger sample of Cepheids in the Large Magellanic Cloud (LMC), a more robust distance to the LMC based on late-type detached eclipsing binaries (DEBs), HST observations of Cepheids in M31, and new HST-based trigonometric parallaxes for Milky Way (MW) Cepheids. We consider four geometric distance calibrations of Cepheids: (i) megamasers in NGC 4258, (ii) 8 DEBs in the LMC, (iii) 15 MW Cepheids with parallaxes measured with HST/FGS, HST/WFC3 spatial scanning and/or Hipparcos, and (iv) 2 DEBs in M31. The Hubble constant from each is 72.25+/-2.51, 72.04+/-2.67, 76.18+/-2.37, and 74.50+/-3.27km/s/Mpc, respectively. Our best estimate of H_0_=73.24+/-1.74km/s/Mpc combines the anchors NGC 4258, MW, and LMC, yielding a 2.4% determination (all quoted uncertainties include fully propagated statistical and systematic components). This value is 3.4{sigma} higher than 66.93+/-0.62km/s/Mpc predicted by {Lambda}CDM with 3 neutrino flavors having a mass of 0.06eV and the new Planck data, but the discrepancy reduces to 2.1{sigma} relative to the prediction of 69.3+/-0.7km/s/Mpc based on the comparably precise combination of WMAP+ACT+SPT+BAO observations, suggesting that systematic uncertainties in CMB radiation measurements may play a role in the tension. If we take the conflict between Planck high-redshift measurements and our local determination of H_0_ at face value, one plausible explanation could involve an additional source of dark radiation in the early universe in the range of {Delta}N_eff_~0.4-1. We anticipate further significant improvements in H_0_ from upcoming parallax measurements of long-period MW Cepheids.
