- ID:
- ivo://CDS.VizieR/J/A+AS/126/471
- Title:
- HI data of galaxies from Kazarian's lists
- Short Name:
- J/A+AS/126/471
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 21-cm neutral hydrogen line has been measured for the first time in 39 non-Seyfert type galaxies from Kazarian list, with the Nancay radiotelescope. The line profiles, widths at 20% and 50% of the peak intensity, radial velocities as well as total fluxes are presented. The values of radial velocity are in fairly good agreement with those obtained from optical spectra. The width values at 20% of the peak vary in wide range from 113km/s (KAZ 579) to 608km/s for KAZ 566. Nine of our objects remained undetected, whether their HI-flux was too faint, the integration time too short, or the frequency sighted wrong. However, for part of them, there were positive hint of detection. Comments on individual objects are given.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/307/236
- Title:
- HI data of Puppis galaxies
- Short Name:
- J/MNRAS/307/236
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report 21-cm H I line observations of 161 galaxies located behind the Milky Way, in the Puppis region. The observations have been carried out with the Nancay radio telescope, resulting in 101 detections. Most of the galaxies observed appear in the ESO catalogue, and present apparent diameters larger than 1.6arcmin. We show that the detection rate is strongly related to the apparent diameter; it is as high as 76 per cent for diameters larger than 1.6arcmin. Half of the non-detections result, in fact, from an insufficient velocity coverage. Global parameters of the detected galaxies are computed, after a careful discussion of the correction for Galactic absorption.
1493. HIDEEP survey
- ID:
- ivo://CDS.VizieR/J/MNRAS/346/787
- Title:
- HIDEEP survey
- Short Name:
- J/MNRAS/346/787
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out an extremely long integration time (9000s/beam) 21-cm blind survey of 60deg^2^ in Centaurus using the Parkes multibeam system. We find that the noise continues to fall as sqrt(t_obs_) throughout, enabling us to reach an H I column-density limit of 4.2x10^18^cm^-2^ for galaxies with a velocity width of 200km/s in the central 32deg^2^ region, making this the deepest survey to date in terms of column density sensitivity. The H I data are complemented by very deep optical observations from digital stacking of multi-exposure UK Schmidt Telescope R-band films, which reach an isophotal level of 26.5Rmag/arcsec^2^ (27.5Bmag/arcsec^2^). 173 H I sources have been found, 96 of which have been uniquely identified with optical counterparts in the overlap area.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A94
- Title:
- HI-detected Coma and field galaxies properties
- Short Name:
- J/A+A/659/A94
- Date:
- 14 Mar 2022 06:46:08
- Publisher:
- CDS
- Description:
- We present the blind Westerbork Coma Survey probing the HI content of the Coma galaxy cluster with the Westerbork Synthesis Radio Telescope. The survey covers the inner ~1Mpc around the cluster centre, extending out to 1.5Mpc towards the south-western NGC 4839 group. The survey probes the atomic gas in the entire Coma volume down to a sensitivity of ~10^19^cm^-2^ and 10^8^M_{sun}_. Combining automated source finding with source extraction at optical redshifts and visual verification, we obtained 40 HI detections of which 24 are new. Over half of the sample displays perturbed HI morphologies indicative of an ongoing interaction with the cluster environment. With the use of ancillary UV and mid-IR, data we measured their stellar masses and star formation rates and compared the HI properties to a set of field galaxies spanning a similar stellar mass and star formation rate range. We find that ~75% of HI-selected Coma galaxies have simultaneously enhanced star formation rates (by ~0.2dex) and are HI deficient (by ~0.5dex) compared to field galaxies of the same stellar mass. According to our toy model, the simultaneous HI deficiency and enhanced star formation activity can be attributed to either HI stripping of already highly star forming galaxies on a very short timescale, while their H_2_ content remains largely unaffected, or to HI stripping coupled to a temporary boost of the HI-to-H_2_ conversion, causing a brief starburst phase triggered by ram pressure before eventually quenching the galaxy.
- ID:
- ivo://CDS.VizieR/J/MNRAS/464/3796
- Title:
- HI gas mass fraction estimations
- Short Name:
- J/MNRAS/464/3796
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The application of artificial neural networks (ANNs) for the estimation of HI gas mass fraction (M_HI_/M*) is investigated, based on a sample of 13 674 galaxies in the Sloan Digital Sky Survey (SDSS) with HI detections or upper limits from the Arecibo Legacy Fast Arecibo L-band Feed Array (ALFALFA). We show that, for an example set of fixed input parameters (g-r colour and i-band surface brightness), a multidimensional quadratic model yields M_HI_/M* scaling relations with a smaller scatter (0.22dex) than traditional linear fits (0.32dex), demonstrating that non-linear methods can lead to an improved performance over traditional approaches. A more extensive ANN analysis is performed using 15 galaxy parameters that capture variation in stellar mass, internal structure, environment and star formation. Of the 15 parameters investigated, we find that g-r colour, followed by stellar mass surface density, bulge fraction and specific star formation rate have the best connection with M_HI_/M*. By combining two control parameters, that indicate how well a given galaxy in SDSS is represented by the ALFALFA training set (PR) and the scatter in the training procedure ({sigma}_fit_), we develop a strategy for quantifying which SDSS galaxies our ANN can be adequately applied to, and the associated errors in the M_HI_/M* estimation. In contrast to previous works, our M_HI_/M* estimation has no systematic trend with galactic parameters such as M*, g-r and star formation rate. We present a catalogue of M_HI_/M* estimates for more than half a million galaxies in the SDSS, of which ~150000 galaxies have a secure selection parameter with average scatter in the M_HI_/M* estimation of 0.22dex.
- ID:
- ivo://CDS.VizieR/J/ApJ/817/2
- Title:
- High angular resolution spectroscopy of NGC 1277
- Short Name:
- J/ApJ/817/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nearby lenticular galaxy NGC 1277 is thought to host one of the largest black holes known, however the black hole mass measurement is based on low spatial resolution spectroscopy. In this paper, we present Gemini Near-infrared Integral Field Spectrometer observations assisted by adaptive optics. We map out the galaxy's stellar kinematics within ~440pc of the nucleus with an angular resolution that allows us to probe well within the region where the potential from the black hole dominates. We find that the stellar velocity dispersion rises dramatically, reaching ~550km/s at the center. Through orbit-based, stellar-dynamical models we obtain a black hole mass of (4.9+/-1.6)x10^9^M_{sun}_ (1{sigma} uncertainties). Although the black hole mass measurement is smaller by a factor of ~3 compared to previous claims based on large-scale kinematics, NGC 1277 does indeed contain one of the most massive black holes detected to date, and the black hole mass is an order of magnitude larger than expectations from the empirical relation between black hole mass and galaxy luminosity. Given the galaxy's similarities to the higher redshift (z~2) massive quiescent galaxies, NGC 1277 could be a relic, passively evolving since that period. A population of local analogs to the higher redshift quiescent galaxies that also contain over-massive black holes may suggest that black hole growth precedes that of the host galaxy.
- ID:
- ivo://CDS.VizieR/J/A+A/363/887
- Title:
- High frequency peakers. I. The bright sample
- Short Name:
- J/A+A/363/887
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Here we present a sample of sources with convex radio spectra peaking at frequencies above a few GHz. We call these radio sources High Frequency Peakers (HFPs). This sample extends to higher turnover frequencies than the samples of Compact Steep Spectrum (CSS) and GHz Peaked Spectrum (GPS) radio sources. HFPs are rare due to the strong bias against them caused by their turnover occurring at frequencies about one order of magnitude higher than in CSS-GPS samples. he sample has been selected by a comparison between the Green Bank survey (87GB) at 4.9 GHz and the NRAO VLA Sky Survey (NVSS) at 1.4 GHz. Then the candidates have been observed with the VLA at 1.365, 1.665, 4.535, 4.985, 8.085, 8.485, 14.96 and 22.46 GHz in order to derive a simultaneous radio spectrum, and remove variable sources from the sample. The final list of genuine HFP sources consists of 55 objects with flux density exceeding 300 mJy at 4.9 GHz at the time of the 87GB observation. Optical identifications are available for 29 of them; 24 are high redshift quasars, 3 are galaxies (one of them has indeed broad lines in the optical spectrum) and 2 are BL Lac objects. The remaining sources are mostly empty fields (17) on the digitised POSS or have uncertain classification (9).
- ID:
- ivo://CDS.VizieR/J/AN/330/223
- Title:
- High frequency peakers. The faint sample
- Short Name:
- J/AN/330/223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of sources with convex radio spectra peaking at frequencies above a few GHz, known as "High Frequency Peakers" (HFPs). A "bright" sample with a flux density limit of 300mJy at 5GHz has been presented by Dallacasa et al. (2000, Cat. J/A+A/363/887). Here we present the "faint" sample with flux density between 50 and 300mJy at 5GHz, restricted to the area around the North Galactic Cap, where the FIRST catalogue is available. The candidates have been observed with the VLA at several frequencies ranging from 1.4 to 22GHz, in order to derive a simultaneous radio spectrum. The final list of confirmed HFP sources consists of 61 objects.
- ID:
- ivo://CDS.VizieR/J/A+A/622/A106
- Title:
- High-redshift candidate Herschel sources
- Short Name:
- J/A+A/622/A106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new catalog of high-redshift candidate Herschel sources. Our sample is obtained after applying a multifrequency filtering method (matched multifilter), which is designed to improve the signal-to-noise ratio (SNR) of faint extragalactic point sources. The method is tested against already-detected sources from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) and used to search for new high-redshift candidates. The multifilter technique produces also an estimation of the photometric redshift of the sources. When compared with a sample of sources with known spectroscopic redshift, the photometric redshift returned from the multifilter is unbiased in the redshift range 0.8<z<4.3. Using simulated data we reproduce the same unbiased result in roughly the same redshift range and determined the error (and bias above z=4) in the photometric redshifts. Based on the multifilter technique, and a selection based on color, flux, and agreement of fit between the observed photometry and assumed SED, we find 370 robust candidates to be relatively bright high-redshift sources. A second sample with 237 objects focuses on the faint end at high-redshift. These 237 sources were previously near the H-ATLAS detection limit but are now confirmed with our technique as high significance detections. Finally, we look for possible lensed Herschel sources by cross-correlating the first sample of 370 objects with two different catalogs of known low-redshift objects, the redMaPPer Galaxy Cluster Catalog and a catalog of galaxies with spectroscopic redshift from the Sloan Digital Sky Survey Data Release 14. Our search renders a number of candidates to be lensed systems from the SDSS cross-correlation but none from the redMaPPeR confirming the more likely galactic nature of the lenses.
- ID:
- ivo://CDS.VizieR/J/ApJ/725/394
- Title:
- High-redshift Ly{alpha} emitters
- Short Name:
- J/ApJ/725/394
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an atlas of 88 z~5.7 and 30 z~6.5 Ly{alpha} emitters obtained from a wide-field narrowband survey. We combined deep narrowband imaging in 120{AA} bandpass filters centered at 8150{AA} and 9140{AA} with deep BVRIz broadband imaging to select high-redshift galaxy candidates over an area of 4180arcmin^2^. The goal was to obtain a uniform selection of comparable depth over the seven targeted fields in the two filters. For the GOODS-North region of the Hubble Deep Field-North field, we also selected candidates using a 120{AA} filter centered at 9210{AA}. We made spectroscopic observations with Keck DEIMOS of nearly all the candidates to obtain the final sample of Ly{alpha} emitters. At the 3.3{AA} resolution of the DEIMOS observations the asymmetric profile for Ly{alpha} emission can be clearly seen in the spectra of nearly all the galaxies. We show that the spectral profiles are surprisingly similar for many of the galaxies and that the composite spectral profiles are nearly identical at z=5.7 and z=6.5.
