- ID:
- ivo://CDS.VizieR/J/A+AS/115/235
- Title:
- The Hamburg/ESO survey for bright QSOs. II.
- Short Name:
- J/A+AS/115/235
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report about the first phase of a wide-angle survey for bright QSOs (12.5<~B<~17.5) in the southern hemisphere, based on objective prism plates taken with the ESO Schmidt telescope over an effective area of ~1000 sq.deg. After digitisation, the extracted spectra were searched for quasar candidates in a largely automated two-stage procedure. Several selection criteria, such as UV excess or presence of emission lines, were applied simultaneously to the databases. Thanks to the high spectral resolution of the spectra, the stellar contamination in the candidate sets could be efficiently kept low. Follow-up spectroscopy has yielded 160 newly discovered QSOs and Seyfert 1 galaxies, plus a variety of other interesting galactic and extragalactic objects. Although the present QSO sample is not statistically "complete" insofar as it has no well-defined flux limit, there is no evidence for strong redshift-dependent selection biases. The extension of the survey over an area of 5000sq.deg. and the construction of flux-limited subsamples are under way.
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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+AS/134/483
- Title:
- The Hamburg Quasar Survey. III.
- Short Name:
- J/A+AS/134/483
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table 3 lists for all new QSOs the position for equinox 2000.0 with an accuracy ~2", the B magnitude obtained from the Schmidt plates with an accuracy ~<0.5 (see Paper I, Hagen et al., 1995A&AS..111..195H), the redshift, and the number of the campaign of Table 2 in which the data were obtained.
- 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/AJ/127/180
- Title:
- The Hawaii Hubble Deep Field North
- Short Name:
- J/AJ/127/180
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a deep multicolor imaging survey of 0.2deg^2^ centered on the Hubble Deep Field North (HDF-N). We shall refer to this region as the Hawaii HDF-N. Deep data were collected in U, B, V, R, I, and z' bands over the central 0.2deg^2^ and in HK' over a smaller region covering the Chandra Deep Field North. The data were reduced to have accurate relative photometry and astrometry across the entire field to facilitate photometric redshifts and spectroscopic follow-up. We have compiled a catalog of 48858 objects in the central 0.2deg^2^ detected at 5{sigma} significance in a 3" aperture in either R or z' band. Number counts and color-magnitude diagrams are presented and shown to be consistent with previous observations. Using color selection we have measured the density of objects at 3<z<7. Our multicolor data indicates that samples selected at z>5.5 using the Lyman break technique suffer from more contamination by low-redshift objects than suggested by previous studies.
- ID:
- ivo://nasa.heasarc/skyview/hawaii-hdf-b
- Title:
- The Hawaii Hubble Deep Field North: Band B
- Short Name:
- Hawaii HDF B
- Date:
- 09 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Hawaii-HDF-N is an intensive multi-color imaging survey of 0.2 sq. degrees centered on the HDF-N. Data were collected on the NOAO 4m Mayall telescope, the National Astronomical Observatory of Japan 8.2m Subaru telescope and the University of Hawaii 2.2m telescope. Deep U, B, V, R, I, and z' data were obtained over the whole field and deep HK' data over the Chandra Deep Field North. Details are available in the references. [Adapted from reference website.] <P> Two different images are given in the V band (V0201 and V0401) from observations separated by about a month that had substantial differences in seeing. Provenance: Data downloaded from the reference website. A formatting error in the FITS files was corrected.. This is a service of NASA HEASARC.
- 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.
