- ID:
- ivo://CDS.VizieR/J/ApJ/812/114
- Title:
- Grism Lens-Amplified Survey from Space (GLASS). I.
- Short Name:
- J/ApJ/812/114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We give an overview of the Grism Lens Amplified Survey from Space (GLASS), a large Hubble Space Telescope program aimed at obtaining grism spectroscopy of the fields of 10 massive clusters of galaxies at redshift z=0.308-0.686, including the Hubble Frontier Fields (HFF). The Wide Field Camera 3 (WFC3) yields near-infrared spectra of the cluster cores covering the wavelength range 0.81-1.69{mu}m through grisms G102 and G141, while the Advanced Camera for Surveys in parallel mode provides G800L spectra of the infall regions of the clusters. The WFC3 spectra are taken at two almost orthogonal position angles in order to minimize the effects of confusion. After summarizing the scientific drivers of GLASS, we describe the sample selection as well as the observing strategy and data processing pipeline. We then utilize MACS J0717.5+3745, a HFF cluster and the first one observed by GLASS, to illustrate the data quality and the high-level data products. Each spectrum brighter than H_AB_=23 is visually inspected by at least two co-authors and a redshift is measured when sufficient information is present in the spectra. Furthermore, we conducted a thorough search for emission lines through all of the GLASS WFC3 spectra with the aim of measuring redshifts for sources with continuum fainter than H_AB_=23. We provide a catalog of 139 emission-line-based spectroscopic redshifts for extragalactic sources, including three new redshifts of multiple image systems (one probable, two tentative).
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/655/790
- Title:
- Groups of galaxies in 2MASS survey
- Short Name:
- J/ApJ/655/790
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of applying a percolation algorithm to the initial release of the Two Micron All Sky Survey Extended Source Catalog, using subsequently measured redshifts for almost all of the galaxies with K<11.25mag. This group catalog is based on the first near-IR all-sky flux-limited survey that is complete to |b|=5{deg}. We explore the dependence of the clustering on the length and velocity scales involved. The paper describes a group catalog, complete to a limiting redshift of 104km/s, created by maximizing the number of groups containing three or more members. A second catalog is also presented, created by requiring a minimum density contrast of {delta}{rho}/{rho}>=80 to identify groups. We identify known nearby clusters in the catalogs and contrast the groups identified in the two catalogs. We examine and compare the properties of the determined groups and verify that the results are consistent with the UZC-SSRS2 and northern CfA redshift survey group catalogs. The all-sky nature of the catalog will allow the development of a flow-field model based on the density field inferred from the estimated cluster masses.
- ID:
- ivo://CDS.VizieR/J/ApJ/669/L33
- Title:
- H{alpha} emission sources in h and {chi} Per
- Short Name:
- J/ApJ/669/L33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of accretion disks associated with ~13Myr old intermediate/low-mass stars in h and {chi} Persei. Optical spectroscopy of ~5000 stars in these clusters and a surrounding halo population reveal 32 A-K stars with Halpha emission. Matching these stars with 2MASS and optical photometry yields 25 stars with the highest probability of cluster membership and EW(Halpha)>=5{AA}. Sixteen of these sources have EW(Halpha)>=10{AA}.
- ID:
- ivo://CDS.VizieR/J/ApJ/677/169
- Title:
- H{alpha} galaxies at z=0.84
- Short Name:
- J/ApJ/677/169
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an H{alpha} near-infrared narrowband survey searching for star-forming galaxies at redshift z=0.84. This work is an extension of our previous narrowband studies in the optical at lower redshifts. After removal of stars and redshift interlopers (using spectroscopic and photometric redshifts), we build a complete sample of 165 H{alpha} emitters in the extended Groth strip and GOODS-N fields with L(H{alpha})>10^41^ergs/s. We compute the H{alpha} luminosity function at z=0.84 after corrections for [NII] flux contamination, extinction, systematic errors, and incompleteness. Our sources present an average dust extinction of A(H{alpha})=1.5mag. Adopting H{alpha} as a surrogate for the instantaneous SFR, we measure an extinction-corrected SFR density of 0.17^+0.03^_-0.03_M_{sun}_/yr/Mpc^3^. Combining this result to our prior measurements at z=0.02, 0.24, and 0.40, we derive an H{alpha}-based evolution of the SFR density proportional to (1+z)^{beta}^ with {beta}=3.8+/-0.5. This evolution is consistent with that derived by other authors using different SFR tracers.
- ID:
- ivo://CDS.VizieR/J/AJ/123/2597
- Title:
- H{alpha} stars and HH objects near BRCs
- Short Name:
- J/AJ/123/2597
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Bright-rimmed clouds (BRCs) found in H II regions are probably sites of triggered star formation due to compression by ionization/shock fronts. Many BRCs harbor IRAS point sources of low dust temperature. They also frequently contain a small cluster of near-IR stars that is elongated along the axis of the BRC. Here we present the results of our H{alpha} grism spectroscopy and narrowband imaging observations of BRCs in search of candidate premain-sequence stars of the T Tauri, Herbig Ae/Be and related types, and Herbig-Haro (HH) objects. We have detected a large number (460) of H{alpha} emission stars down to a limiting magnitude of about R=20 in and around all but two of the 28 BRCs observed. The present study has, for the first time, reached down nearly to the faintest classical T Tauri star population in OB associations. A total of 12 new HH objects have been found.
- ID:
- ivo://CDS.VizieR/J/AJ/135/2323
- Title:
- H{alpha} stars and HH objects near BRCs
- Short Name:
- J/AJ/135/2323
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out near-IR/optical observations to examine star formation toward a bright-rimmed cometary globule (BRC37) facing the exciting star(s) of an HII region (IC1396) containing an IRAS source, which is considered to be an intermediate-mass protostar. With slitless spectroscopy we detected ten H{alpha} emission stars around the globule, six of which are near the tip of the globule and are aligned along the direction to the exciting stars.
- ID:
- ivo://CDS.VizieR/J/A+A/546/A64
- Title:
- H and K-band stacked spectra of U/LIRGs
- Short Name:
- J/A+A/546/A64
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an atlas of a sample of local (z<0.1) LIRGs (10) and ULIRGs (7) covering the luminosity range log(L_IR_\L_{sun}_)=11.1-12.4. The atlas is based on near-infrared H (1.45-1.85um) and K-band (1.95-2.45um) VLT-SINFONI integral field spectroscopy. The atlas presents the ionised, partially ionised, and warm molecular gas 2D flux distributions and kinematics over a FoV of ~3x3kpc (LIRGs) and ~12x12kpc (ULIRGs) and with average linear resolutions of ~0.2kpc and ~0.9kpc, respectively. The different phases of the gas show a wide morphological variety with the nucleus as the brightest Br_g source for ~33% of the LIRGs and ~71% of the ULIRGs, whereas all the LIRGs and ULIRGs have their maximum H_2_ emission in their nuclear regions. In LIRGs, the ionised gas distribution is dominated by the emission from the star-forming rings or giant HII regions in the spiral arms. The Br_g_ and [FeII] line at 1.644um trace the same structures, although the emission peaks at different locations in some of the objects, and the [FeII] seems to be more extended and diffuse. The ULIRG subsample is at larger distances and contains mainly pre-coalescence interacting systems. Although the peaks of the molecular gas emission and the continuum coincide in ~71% of the ULIRGs, regions with intense Pa_a_ (Br_g_) emission tracing luminous star-forming regions located at distances of 2-4kpc away from the nucleus are also detected, usually associated with secondary nuclei or tidal tails. LIRGs have mean observed (i.e. uncorrected for internal extinction) SFR surface densities of about 0.4 to 0.9M_{sun}_/yr/kpc^2^ over large areas (4-9kpc^2^) with peaks of about 2-2.5M_{sun}_/yr/kpc^2^ in the smaller regions (0.16kpc^2^) associated with the nucleus of the galaxy or the brightest Br_g_ region. ULIRGs do have similar average SFR surface densities for the integrated emitting regions of ~0.4M_{sun]_/yr/kpc^2^ in somewhat larger areas (100-200kpc^2^) and for the Pa_a peak (~2M_{sun}_/yr/kpc^2^ in 4kpc^2^). The observed gas kinematics in LIRGs is primarily due to rotational motions around the centre of the galaxy, although local deviations associated with radial flows and/or regions of higher velocity dispersions are present. The ionised and molecular gas share the same kinematics (velocity field and velocity dispersion) to first order, showing slight differences in the velocity amplitudes (peak-to-peak) in some cases, whereas the average velocity dispersions are compatible within uncertainties. As expected, the kinematics of the ULIRG subsample is more complex, owing to the interacting nature of the objects of the sample.
- ID:
- ivo://CDS.VizieR/J/A+A/559/L2
- Title:
- H and Ks maps aroung G045.47+0.05
- Short Name:
- J/A+A/559/L2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As a continuation of a previous work, in which we found strong evidence of massive molecular outflows towards a massive star forming site, we present a new study of this region based on very high angular resolution observations with the aim of discovering the outflow driven mechanism. Using near-IR data acquired with Gemini-NIRI at the broad H- and Ks-bands, we study a region of 22"x22" around the UCHII region G045.47+0.05, a massive star forming site at the distance of about 8kpc. To image the source with the highest spatial resolution possible we employed the adaptative optic system ALTAIR, achieving an angular resolution of about 0.15". We discovered a cone-like shape nebula with an opening angle of about 90{deg} extending eastwards the IR source 2MASS J19142564+1109283, a very likely MYSO. This morphology suggests a cavity that was cleared in the circumstellar material and its emission may arise from scattered continuum light, warm dust, and likely emission lines from shock-excited gas. The nebula, presenting arc-like features, is connected with the IR source through a jet-like structure, which is aligned with the blue shifted CO outflow found in a previous study. The near-IR structure lies ~3" north of the radio continuum emission, revealing that it is not spatially coincident with the UCHII region. The observed morphology and structure of the near-IR nebula strongly suggest the presence of a precessing jet. In this study we have resolved the circumstellar ambient (in scale of a thousand A.U.) of a distant MYSO, indeed one of the farthest cases.
- ID:
- ivo://CDS.VizieR/J/ApJ/749/65
- Title:
- H-ATLAS search for strongly lensed galaxies
- Short Name:
- J/ApJ/749/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- While the selection of strongly lensed galaxies (SLGs) with 500{mu}m flux density S_500_>100mJy has proven to be rather straightforward, for many applications it is important to analyze samples larger than the ones obtained when confining ourselves to such a bright limit. Moreover, only by probing to fainter flux densities is it possible to exploit strong lensing to investigate the bulk of the high-z star-forming galaxy population. We describe HALOS (the Herschel-ATLAS Lensed Objects Selection), a method for efficiently selecting fainter candidate SLGs, reaching a surface density of =~1.5-2/deg^2^, i.e., a factor of about 4-6 higher than that at the 100mJy flux limit. HALOS will allow the selection of up to ~1000 candidate SLGs (with amplifications {mu}>~2) over the full H-ATLAS survey area. Applying HALOS to the H-ATLAS Science Demonstration Phase field (=~14.4deg^2^) we find 31 candidate SLGs, whose candidate lenses are identified in the VIKING near-infrared catalog. Using the available information on candidate sources and candidate lenses we tentatively estimate a =~72% purity of the sample. As expected, the purity decreases with decreasing flux density of the sources and with increasing angular separation between candidate sources and lenses. The redshift distribution of the candidate lensed sources is close to that reported for most previous surveys for lensed galaxies, while that of candidate lenses extends to redshifts substantially higher than found in the other surveys. The counts of candidate SLGs are also in good agreement with model predictions. Even though a key ingredient of the method is the deep near-infrared VIKING photometry, we show that H-ATLAS data alone allow the selection of a similarly deep sample of candidate SLGs with an efficiency close to 50%; a slightly lower surface density (=~ 1.45/deg2) can be reached with a ~70% efficiency.
- ID:
- ivo://CDS.VizieR/J/ApJS/201/19
- Title:
- Hawaii Infrared Parallax Program. I.
- Short Name:
- J/ApJS/201/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Astrometry and photometry for 318 ultracool dwarfs in 265 systems that have measured trigonometric parallaxes. To be included in this tabulation, an object must have a spectral type >=M6 or a K-band absolute magnitude >8.5mag. Parallaxes, proper motions, and coordinates at a specified epoch are given for all objects. Photometric measurements in MKO, 2MASS, Spitzer, and WISE systems are given when available. Various other flags that provide additional information about the object or photometry are included.
