- ID:
- ivo://CDS.VizieR/J/AJ/160/242
- Title:
- The H{alpha} dots survey. II. 119 new dots
- Short Name:
- J/AJ/160/242
- Date:
- 09 Mar 2022 22:00:00
- Publisher:
- CDS
- Description:
- We present the second catalog of serendipitously discovered compact extragalactic emission-line sources-H{alpha} Dots. These objects have been discovered in searches of moderately deep narrow-band images acquired for the ALFALFA H{alpha} project. In addition to cataloging 119 new H{alpha} Dots, we also present follow-up spectral data for the full sample. These spectra allow us to confirm the nature of these objects as true extragalactic emission-line objects, to classify them in terms of activity type (star-forming or AGN), and to identify the emission line via which they were discovered. We tabulate photometric and spectroscopic data for the all objects, and we present an overview of the properties of the full H{alpha} Dot sample. The H{alpha} Dots represent a broad range of star-forming and active galaxies detected via several different emission lines over a wide range of redshifts. The sample includes H{alpha}-detected blue compact dwarf galaxies at low redshift, [OIII]-detected Seyfert 2 and Green Pea-like galaxies at intermediate redshifts, and QSOs detected via one of several UV emission lines, including Ly{alpha}. Despite the heterogeneous appearance of the resulting catalog of objects, we show that our selection method leads to well-defined samples of specific classes of emission-line objects with properties that allow for statistical studies of each class.
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- ID:
- ivo://CDS.VizieR/J/A+AS/128/507
- Title:
- The Hamburg Quasar Survey. II.
- Short Name:
- J/A+AS/128/507
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hamburg Quasar Survey is a wide-angle objective prism survey for finding bright QSOs in the northern extragalactic sky (|b|>20{deg}; {delta}>0{deg}). The taking of the prism plates for 567 fields covering this area was completed in 1997. Including direct plates for fields with {delta}> 20{deg} the plate archive contains now 1871 plates. In this paper we present a first list of 121 quasars, which were verified by slit spectroscopy in the years 1986-1991, while experiments to develop efficient selection techniques were made. The sample contains objects with brightnesses 15<=B<=19.5 and redshifts z<=2.8 collected over various parts of the sky, for which objective prism plates were available at that time.
- ID:
- ivo://CDS.VizieR/J/A+A/397/463
- Title:
- The Hamburg/SAO Survey for BCGs. I.
- Short Name:
- J/A+A/397/463
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the description and the first results of a new project devoted to the search for extremely metal-deficient blue compact/HII-galaxies (BCGs) and to the creation of a well selected large BCG sample with strong emission lines. Such galaxies should be suitable for reliable determination of their oxygen abundance through the measurement of the faint [OIII]4363{AA} line. The goals of the project are two-fold: a) to discover a significant number of new extremely metal-poor galaxies (Z<=1/20Z_{sun}_), and b) to study the metallicity distribution of local BCGs. Selection of candidates for follow-up slit spectroscopy is performed on the database of objective prism spectra of the Hamburg Quasar Survey. The sky region is limited by {delta}>=0{deg} and b^II^<=-30{deg}. In this paper we present the results of the follow-up spectroscopy conducted with the Russian 6m telescope. The list of observed candidates contained 52 objects, of which 46 were confirmed as strong-lined BCGs (EW([OIII]5007>=100{AA}). The remaining five lower excitation ELGs include three BCGs, and two galaxies classified as SBN (Starburst Nucleus) and DANS (Dwarf Amorphous Nucleus Starburst). One object is identified as a quasar with a strong Ly_alpha emission line near {lambda}=5000{AA} (z~3). We provide a list with coordinates, measured radial velocities, B-magnitudes, equivalent widths EW([OIII]5007) and EW(H{beta}) and for the 46 strong-lined BCGs the derived oxygen abundances 12+log(O/H). The abundances range between 7.42 and 8.4 (corresponding to metallicities between 1/30 and 1/3Z_{sun}_). The sample contains four galaxies with Z<=1/20Z_{sun}_, of which three are new discoveries. This demonstrates the high efficiency of the new project to find extremely metal-deficient galaxies. The radial velocities of the strong-lined ELGs range between 500 and 19000km/s with a median value of ~6400km/s. The typical B-magnitudes of the galaxies presented are 17.0mag-18.0mag.
- ID:
- ivo://CDS.VizieR/J/A+AS/135/511
- Title:
- The Hamburg/SAO Survey for ELGs
- Short Name:
- J/A+AS/135/511
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present first results of the Hamburg/SAO Survey for Emission-Line Galaxies (HSS therein, SAO - Special Astrophysical Observatory, Russia) which is based on the digitized objective-prism photoplates database of the Hamburg Quasar Survey (HQS). The main goal of this survey is the search for emission-line galaxies (ELG) in order to create a new deep sample of blue compact galaxies (BCG) in a large sky area. Another important goal of this work is to search for new extremely low-metallicity galaxies. We present the first results of spectroscopy obtained with the 2.2m telescope at the German-Spanish Observatory at Calar Alto, and with the 6m telescope at the Russian Special Astrophysical Observatory. The primary ELG candidate selection criteria applied were a blue continuum (near 4000{AA}) and the presence of emission lines close to 5000A recognized on digitized prism spectra of galaxies with magnitudes in the range B =16.0-19.5. The spectroscopy resulted in the detection or/and quantitative spectral classification of 74 emission-line objects. Of them 55 are newly discovered, and 19 were already known as galaxies before. 11 of the latter have redshifts and are known ELGs. For most of the known galaxies emission line ratios were measured for the first time and an improved classification is presented. 47 objects are classified as BCGs, one as Sy2 galaxy, six as probable LINERs, and four as new QSOs. The remaining galaxies do not show significant H{beta} and [OIII]4959,5007{AA} emission lines, and are likely either low-ionization starburst or dwarf amorphous nuclear starburst galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/366/771
- Title:
- The Hamburg/SAO Survey for ELGs. IV
- Short Name:
- J/A+A/366/771
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the fourth list with results of the Hamburg/SAO Survey for Emission-Line Galaxies (HSS hereafter, SAO -- Special Astrophysical Observatory, Russia). The main goal of the project is the search for emission-line galaxies (ELG) in order to create a new deep sample of blue compact/HII galaxies (BCG) in a large sky area. Another important goal of this work is to search for new extremely low-metallicity galaxies. The main ELG candidate selection criteria applied are blue or flat enough continuum (near 4000{AA}) and the presence of strong or moderate emission lines close to 5000{AA} recognized on digitized prism spectra of galaxies with the survey estimated B-magnitudes in the range 16-19.5. No other criteria were applied. The list is a result of the follow-up spectroscopy conducted with the 6m SAO RAS telescope in 1998, 1999 and 2000. The data of this snap-shot spectroscopy survey confirmed 127 emission-line objects out of 176 observed candidates and allowed their quantitative spectral classification. We could classify 76 emission-line objects as BCG/HII galaxies or probable BCGs, 8 as QSOs, 2 as Seyfert galaxies, 2 as super-associations in a subluminous spiral and an irregular galaxy, and 37 as low-excitation objects - either starburst nuclei (SBN), or dwarf amorphous nuclei starburst galaxies (DANS). We could not classify 2 ELGs. Furthermore, for 5 galaxies we did not detect any significant emission lines. For 91 emission-line galaxies, the redshifts and/or line intensities are determined for the first time. Of the remaining 28 previously known ELGs we give either improved data on the line intensities or some independent measurements.
- ID:
- ivo://CDS.VizieR/J/A+A/374/907
- Title:
- The Hamburg/SAO Survey for ELGs. V.
- Short Name:
- J/A+A/374/907
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the fifth list with results of the Hamburg/SAO Survey for Emission-Line Galaxies (HSS therein, SAO - Special Astrophysical Observatory, Russia). The list is a result of follow-up spectroscopy conducted with the 2.2m CAHA and 4m Kitt Peak telescopes in 1999. The data of this snap-shot spectroscopy survey confirmed 166 emission-line objects out of 209 observed candidates and allowed their quantitative spectral classification and redshift determination. We could classify 98 emission-line objects as BCG/HII galaxies or probable BCGs, 5 as QSOs, 3 as Seyfert galaxies, 2 as super-associations in subluminous spiral galaxies. 25 low-excitation objects were classified as starburst nuclei (SBN), 24 as dwarf amorphous nuclei starburst galaxies (DANS) and 3 as LINERs. Due to low signal-to-noise ratio we could not classify 6 ELGs. Furthermore, for another 4 galaxies we did not detect any significant emission lines. For 131 emission-line galaxies, the redshifts and/or line intensities are determined for the first time. For the remaining 30 previously known ELGs we give either improved data of the line intensities or some independent measurements.
- ID:
- ivo://CDS.VizieR/J/ApJS/94/461
- Title:
- The Hawai K-band survey. III.
- Short Name:
- J/ApJS/94/461
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectra and multicolor (B,I,K) data for near-infrared (K) selected spatially complete magnitude limited (K<20) galaxy samples from the Hawaii Survey. The redshift identification of the sample of 298 galaxies is substantially complete to a B magnitude of 26 and an I magnitude of 22.5, and identification of observed galaxies ranges from nearly 100% completeness at K<18 to ~70% completeness at K=19-20. We note that many of the unidentified objects appear to be red (I-K) objects which are flat in the optical and spectroscopically featureless. Strengths of spectral-line features and breaks are tabulated for the 262 galaxies with reasonably secure redshifts. The measured redshifts nearly all fall at z<1, with the exception of a compact absorption-line object at z=2.35. At K>=18, the redshift distribution is well fitted by a model with no luminosity evolution, implying that from the K-band Hubble diagram, the Hubble constant can vary at most by 10% over the redshift range from z~0.025 to 0.25, and that positive luminosity evolution at any significant level between z=0 and z=1 is ruled out. However, the evolution of both the emission-line strengths and the 4000{AA} break indicates that galaxies were undergoing significantly more star formation at z=1 than at the present time.
- ID:
- ivo://CDS.VizieR/J/ApJ/891/129
- Title:
- The HeCS-omnibus catalog: SDSS & MMT sp. obs.
- Short Name:
- J/ApJ/891/129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore connections between brightest cluster galaxies (BCGs) and their host clusters. We first construct a HeCS-omnibus cluster sample including 227 galaxy clusters within 0.02<z<0.30; the total number of spectroscopic members from MMT/Hectospec and SDSS observations is 52325. Taking advantage of the large spectroscopic sample, we compute physical properties of the clusters including the dynamical mass and cluster velocity dispersion ({sigma}_cl_). We also measure the central stellar velocity dispersion of the BCGs ({sigma}_*,BCGs_) to examine the relation between BCG velocity dispersion and cluster velocity dispersion for the first time. The observed relation between BCG velocity dispersion and the cluster velocity dispersion is remarkably tight. Interestingly, the {sigma}_*,BCG_/{sigma}_cl_ ratio decreases as a function of {sigma}_cl_ unlike the prediction from the numerical simulation of Dolag+ (2010MNRAS.405.1544D). The trend in {sigma}_*,BCG_/{sigma}_cl_ suggests that BCG formation is more efficient in lower mass halos.
- ID:
- ivo://CDS.VizieR/J/ApJ/856/172
- Title:
- The HectoMAP cluster survey. I.
- Short Name:
- J/ApJ/856/172
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the dense HectoMAP redshift survey to explore the properties of 104 redMaPPer cluster candidates. The redMaPPer systems in HectoMAP cover the full range of richness and redshift (0.08<z<0.60). Fifteen of the systems included in the Subaru/Hyper Suprime-Cam public data release are bona fide clusters. The median number of spectroscopic members per cluster is ~20. We include redshifts of 3547 member candidates listed in the redMaPPer catalog whether they are cluster members or not. We evaluate the redMaPPer membership probability spectroscopically. The purity (number of real systems) in redMaPPer exceeds 90% even at the lowest richness. Three massive galaxy clusters (M~2x10^13^M_{sun}_) associated with X-ray emission in the HectoMAP region are not included in the public redMaPPer catalog with {lambda}_rich_>20, because they lie outside the cuts for this catalog.
- ID:
- ivo://CDS.VizieR/J/ApJ/855/100
- Title:
- The HectoMAP cluster survey. II. X-ray clusters
- Short Name:
- J/ApJ/855/100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We apply a friends-of-friends algorithm to the HectoMAP redshift survey and cross-identify associated X-ray emission in the ROSAT All-Sky Survey data (RASS). The resulting flux-limited catalog of X-ray cluster surveys is complete to a limiting flux of ~3x10^-13^erg/s/cm^2^ and includes 15 clusters (7 newly discovered) with redshifts z<=0.4. HectoMAP is a dense survey (~1200 galaxies deg^-2^) that provides ~50 members (median) in each X-ray cluster. We provide redshifts for the 1036 cluster members. Subaru/Hyper Suprime-Cam imaging covers three of the X-ray systems and confirms that they are impressive clusters. The HectoMAP X-ray clusters have an LX-{sigma}cl scaling relation similar to that of known massive X-ray clusters. The HectoMAP X-ray cluster sample predicts ~12000+/-3000 detectable X-ray clusters in RASS to the limiting flux, comparable with previous estimates.
