- ID:
- ivo://CDS.VizieR/J/A+AS/142/417
- Title:
- Hamburg/SAO Survey for ELGs. III.
- Short Name:
- J/A+AS/142/417
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the third list with results of the Hamburg/SAO Survey for Emission-Line Galaxies (HSS therein, SAO - Special Astrophysical Observatory, Russia). This survey is based on the digitized objective-prism photoplate database of the Hamburg Quasar Survey (HQS). Here, we present new spectroscopic results of candidates which were obtained in 1998 with the 2.1m KPNO and the 2.2m Calar Alto telescopes. All candidates are selected in the declination band +35{deg} to +40{deg}. The follow-up spectroscopy with the 2m class telescopes confirmed 85 emission-line objects out of 113 observed candidates and allowed their quantitative spectral classification. For 80 of them, the redshifts are determined for the first time. For 5 previously known Emission-Line Galaxies (ELGs), line ratios are presented for the first time. We could classify 55 out of the 85 emission-line objects as BCG/HII galaxies or probable BCGs (Blue Compact Galaxies) , 4 - as QSOs, 6 - as Seyfert galaxies, 1 - as super-association in a subluminous spiral galaxy, and 11 are low-excitation objects - either starburst nuclei (SBN), or dwarf amorphous nuclei starburst galaxies (DANS). We could not classify 8 ELGs. Further, for 8 more galaxies we did not detect any significant emission lines.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/442/109
- Title:
- Hamburg/SAO Survey for ELGs. VI.
- Short Name:
- J/A+A/442/109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the sixth list with results of the Hamburg/SAO Survey for Emission-Line Galaxies. The final list resulted from follow-up spectroscopy conducted with the 4.5m MMT telescope in 1996, and with 2.2m CAHA and 6m SAO telescopes in 2000 to 2003. The data of this snap-shot spectroscopy survey confirmed 134 emission-line objects out of 182 observed candidates and allowed their quantitative spectral classification and redshift determination. We classify 73 emission-line objects as definite or probable blue compact or HII galaxies (BCG), 8 as QSOs, 4 as Seyfert 1 and 2 galaxies. 30 low-excitation objects were classified as definite or probable starburst nuclei (SBN), 3 as dwarf amorphous nuclei starburst galaxies (DANS) and 2 as LINERs. Due to the low signal-to-noise ratio we could not classify 14 ELGs (NON). For another 9 galaxies we did not detect any significant emission lines. For 98 emission-line galaxies, the redshifts and/or line intensities are determined for the first time. For the remaining 28 previously-known ELGs we give either improved data the line intensities or some independent measurements. The detection rate of ELGs is ~70%. This paper completes the classification of strong-lined ELGs found in the zone of the Hamburg/SAO survey. Together with previously known BCG/HII galaxies in this zone, this sample of ~500 objects is the largest to date in a well bound region.
- 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/ApJS/217/5
- Title:
- HAQ survey: red QSO candidates follow-up
- Short Name:
- J/ApJS/217/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Quasi-stellar objects (QSOs) whose spectral energy distributions (SEDs) are reddened by dust either in their host galaxies or in intervening absorber galaxies are to a large degree missed by optical color selection criteria like the ones used by the Sloan Digital Sky Survey (SDSS). To overcome this bias against red QSOs, we employ a combined optical and near-infrared (near-IR) color selection. In this paper, we present a spectroscopic follow-up campaign of a sample of red candidate QSOs which were selected from the SDSS and the UKIRT Infrared Deep Sky Survey (UKIDSS). The spectroscopic data and SDSS/UKIDSS photometry are supplemented by mid-infrared photometry from the Wide-field Infrared Survey Explorer. In our sample of 159 candidates, 154 (97%) are confirmed to be QSOs. We use a statistical algorithm to identify sightlines with plausible intervening absorption systems and identify nine such cases assuming dust in the absorber similar to Large Magellanic Cloud sightlines. We find absorption systems toward 30 QSOs, 2 of which are consistent with the best-fit absorber redshift from the statistical modeling. Furthermore, we observe a broad range in SED properties of the QSOs as probed by the rest-frame 2{mu}m flux. We find QSOs with a strong excess as well as QSOs with a large deficit at rest-frame 2{mu}m relative to a QSO template. Potential solutions to these discrepancies are discussed. Overall, our study demonstrates the high efficiency of the optical/near-IR selection of red QSOs.
- ID:
- ivo://CDS.VizieR/J/ApJ/878/134
- Title:
- HARPS and X-shooter spectra of Southern M dwarfs
- Short Name:
- J/ApJ/878/134
- Date:
- 25 Oct 2021 00:49:19
- Publisher:
- CDS
- Description:
- We present the homogeneous analysis of a sample of Southern early-type M dwarfs in the solar neighborhood (d<60pc). We used the MCAL technique to derive the effective temperature Teff, metallicity [Fe/H], and activity index i_a_(H_alpha_) of 420 M stars using HARPS spectra. The effective temperature Teff, surface gravity logg, metallicity [Fe/H], and projected rotational velocity V_rot_sini of 153 M0-M6 dwarfs were determined by fitting the observed intermediate-resolution spectra from the VIS arm of VLT/X-shooter with a grid of BT-Settl stellar atmosphere models. We estimated the typical uncertainties of the fit with X-shooter spectra by varying region-to-region results by {sigma}T_eff_~50K, {sigma}logg~0.2, and {sigma}[Fe/H]~0.2dex. Photometric verification of Teff for the 295 stars from the HARPS sample and the 61 stars from the X-shooter sample is also provided. We compared our results from different methods to estimate absolute uncertainty in determining the physical properties of M dwarfs.
- ID:
- ivo://CDS.VizieR/J/AJ/160/129
- Title:
- HARPS, HIRES and AAT Radial Velocities of HD 136352
- Short Name:
- J/AJ/160/129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Some of the most scientifically valuable transiting planets are those that were already known from radial velocity (RV) surveys. This is primarily because their orbits are well characterized and they preferentially orbit bright stars that are the targets of RV surveys. The Transiting Exoplanet Survey Satellite (TESS) provides an opportunity to survey most of the known exoplanet systems in a systematic fashion to detect possible transits of their planets. HD136352 (Nu Lupi) is a naked-eye (V=5.78) G-type main-sequence star that was discovered to host three planets with orbital periods of 11.6, 27.6, and 108.1days via RV monitoring with the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph. We present the detection and characterization of transits for the two inner planets of the HD136352 system, revealing radii of 1.482_-0.056_^+0.058^ R{Earth} and 2.608_-0.077_^+0.078^ R{Earth} for planets b and c, respectively. We combine new HARPS observations with RV data from the Keck/High Resolution Echelle Spectrometer and the Anglo-Australian Telescope, along with TESS photometry from Sector 12, to perform a complete analysis of the system parameters. The combined data analysis results in extracted bulk density values of {rho}_b_=7.8_-1.1_^+1.2^g/cm3 and {rho}_c_=3.50_-0.36_^+0.41^g/cm3 for planets b and c, respectively, thus placing them on either side of the radius valley. The combination of the multitransiting planet system, the bright host star, and the diversity of planetary interiors and atmospheres means this will likely become a cornerstone system for atmospheric and orbital characterization of small worlds.
- ID:
- ivo://CDS.VizieR/J/A+A/600/A13
- Title:
- HARPS M dwarf sample magnetic activity
- Short Name:
- J/A+A/600/A13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Atmospheric magnetic fields in stars with convective envelopes heat stellar chromospheres, and thus increase the observed flux in the CaII H and K doublet. Starting with the historical Mount Wilson monitoring program, these two spectral lines have been widely used to trace stellar magnetic activity, and as a proxy for rotation period (Prot) and consequently for stellar age. Monitoring stellar activity has also become essential in filtering out false-positives due to magnetic activity in extra-solar planet surveys. The CaII emission is traditionally quantified through the R'_HK_-index, which compares the chromospheric flux in the doublet to the overall bolometric flux of the star. Much work has been done to characterize this index for FGK-dwarfs, but M dwarfs - the most numerous stars of the Galaxy - were left out of these analyses and no calibration of their CaII H and K emission to an R'_HK_ exists to date. We set out to characterize the magnetic activity of the low- and very-low-mass stars by providing a calibration of the R'_HK_-index that extends to the realm of M dwarfs, and by evaluating the relationship between R'_HK_ and the rotation period.. We calibrated the bolometric and photospheric factors for M dwarfs to properly transform the S-index (which compares the flux in the CaII H and K lines to a close spectral continuum) into the R'_HK_. We monitored magnetic activity through the CaII H and K emission lines in the HARPS M dwarf sample.
- ID:
- ivo://CDS.VizieR/J/AJ/154/237
- Title:
- HARPS-N radial velocities of WASP-47
- Short Name:
- J/AJ/154/237
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present precise radial velocity observations of WASP-47, a star known to host a hot Jupiter, a distant Jovian companion, and, uniquely, two additional transiting planets in short-period orbits: a super-Earth in a ~19 hr orbit, and a Neptune in a ~9 day orbit. We analyze our observations from the HARPS-N spectrograph along with previously published data to measure the most precise planet masses yet for this system. When combined with new stellar parameters and reanalyzed transit photometry, our mass measurements place strong constraints on the compositions of the two small planets. We find that, unlike most other ultra-short-period planets, the inner planet, WASP-47 e, has a mass (6.83+/-0.66 M_{Earth}_) and a radius (1.810+/-0.027 R_{Earth}_) that are inconsistent with an Earth-like composition. Instead, WASP-47 e likely has a volatile-rich envelope surrounding an Earth-like core and mantle. We also perform a dynamical analysis to constrain the orbital inclination of WASP-47 c, the outer Jovian planet. This planet likely orbits close to the plane of the inner three planets, suggesting a quiet dynamical history for the system. Our dynamical constraints also imply that WASP-47 c is much more likely to transit than a geometric calculation would suggest. We calculate a transit probability for WASP-47 c of about 10%, more than an order of magnitude larger than the geometric transit probability of 0.6%.
- ID:
- ivo://CDS.VizieR/J/AJ/155/203
- Title:
- HARPS-N RVs & activity indicators for Kepler-1655
- Short Name:
- J/AJ/155/203
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the confirmation of a small, moderately irradiated (F=155+/-7 F_{Earth}_) Neptune with a substantial gas envelope in a P=11.8728787+/-0.0000085 day orbit about a quiet, Sun-like G0V star Kepler-1655. Based on our analysis of the Kepler light curve, we determined Kepler-1655b's radius to be 2.213+/-0.082 R_{Earth}_. We acquired 95 high-resolution spectra with Telescopio Nazionale Galileo/HARPS-N, enabling us to characterize the host star and determine an accurate mass for Kepler-1655b of 5.0_-2.8_^+3.1^ M_{Earth}_ via Gaussian-process regression. Our mass determination excludes an Earth-like composition with 98% confidence. Kepler-1655b falls on the upper edge of the evaporation valley, in the relatively sparsely occupied transition region between rocky and gas-rich planets. It is therefore part of a population of planets that we should actively seek to characterize further.
- ID:
- ivo://CDS.VizieR/J/A+A/489/1255
- Title:
- HARPS observations of eight galactic Cepheids
- Short Name:
- J/A+A/489/1255
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We show that residual {gamma}-velocities (compared to a axisymmetric rotation model of the milky Way) are an intrinsic property of Cepheids. We observed eight galactic Cepheids with the HARPS spectroscope, focusing specifically on 17 spectral lines. For each spectral line of each star, we computed the {gamma}-velocity (resp. {gamma}-asymmetry) as an average value of the interpolated radial velocity (resp. line asymmetry) curve. For each Cepheid in our sample, a linear relation is found between the {gamma}-velocities of the various spectral lines and their corresponding {gamma}-asymmetries, showing that residual {gamma}-velocities stem from the intrinsic properties of Cepheids. We also provide a physical reference to the stellar {gamma}-velocity: it should be zero when the {gamma}-asymmetry is zero. Following this definition, we provide very precise and physically calibrated estimates of the {gamma}-velocities for all stars of our sample.
