- ID:
- ivo://CDS.VizieR/J/ApJ/679/194
- Title:
- Low-z intergalactic medium. III.
- Short Name:
- J/ApJ/679/194
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We conduct an ultraviolet (HST and FUSE) spectroscopic survey of HI (Lyman lines) and seven metal ions (OVI, NV, CIV, CIII, SiIV, SiIII, FeIII) in the low-redshift IGM at z<0.4. We analyzed 650 Ly{alpha} absorbers over redshift path length {Delta}z=5.27, detecting numerous absorbers: 83 OVI systems, 39 CIII, 53 SiIII, 24 CIV, 24 NV, and so on. In the low-z IGM, we have accounted for ~40% of the baryons: 30% in the photoionized Ly{alpha} forest and 10% in the (T=10^5^-10^6^) WHIM traced by OVI. Statistical metallicities are consistent with the canonical value of 10% solar, with considerable scatter.
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- ID:
- ivo://CDS.VizieR/J/A+A/408/67
- Title:
- LSB galaxies in near-infrared. II.
- Short Name:
- J/A+A/408/67
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A total of 367 Low Surface Brightness galaxies detected in the 2MASS all-sky near-infrared survey have been observed in the 21 cm H I line using the Arecibo telescope. All have a Ks-band mean central surface brightness, measured within a 5" radius, fainter than 18mag/arcsec^2^. We present global H I line parameters for the 107 clearly detected objects and the 21 marginal detections, as well as upper limits for the undetected objects. The 107 clear detections comprise 15 previously uncatalogued objects and 36 with a PGC entry only.
- ID:
- ivo://CDS.VizieR/J/A+A/408/465
- Title:
- LSB galaxies in near-infrared. III.
- Short Name:
- J/A+A/408/465
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A total of 334 Low Surface Brightness galaxies detected in the 2MASS all-sky near-infrared survey have been observed in the 21 cm H I line using the Nancay telescope. All have a Ks-band mean central surface brightness, measured within a 5" radius, fainter than 18mag/arcsec^2^ and a Ks-band isophotal radius at the 20mag/arcsec^2^ level larger than 20". We present global H I line parameters for the 171 clearly detected objects and the 23 marginal detections, as well as upper limits for the undetected objects. The 171 clear detections comprise 50 previously uncatalogued objects and 41 objects with a PGC entry only.
- ID:
- ivo://CDS.VizieR/J/MNRAS/476/4488
- Title:
- LSBG HI and optical properties
- Short Name:
- J/MNRAS/476/4488
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the HI and optical properties of nearby (z<=0.1) Low Surface Brightness galaxies (LSBGs). We started with a literature sample of ~900 LSBGs and divided them into three morphological classes: spirals, irregulars, and dwarfs. Of these, we could use ~490 LSBGs to study their HI and stellar masses, colours, and colour-magnitude diagrams, and local environment, compare them with normal, High Surface Brightness (HSB) galaxies and determine the differences between the three morphological classes. We found that LSB and HSB galaxies span a similar range in HI and stellar masses, and have a similar M_HI_/M_{star}_-M_{star}_ relationship. Among the LSBGs, as expected, the spirals have the highest average HI and stellar masses, both of about 10^9.8^M_{sun}_. The LSGBs' (g-r) integrated colour is nearly constant as function of HI mass for all classes. In the colour-magnitude diagram, the spirals are spread over the red and blue regions whereas the irregulars and dwarfs are confined to the blue region. The spirals also exhibit a steeper slope in the M_HI_/M_{star}_-M_{star}_ plane. Within their local environment, we confirmed that LSBGs are more isolated than HSB galaxies, and LSB spirals more isolated than irregulars and dwarfs. Kolmogorov-Smirnov statistical tests on the HI mass, stellar mass, and number of neighbours indicate that the spirals are a statistically different population from the dwarfs and irregulars. This suggests that the spirals may have different formation and HI evolution than the dwarfs and irregulars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/479/3509
- Title:
- LVHIS. far-infrared radio correlation
- Short Name:
- J/MNRAS/479/3509
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we measure the far-infrared (FIR) and radio flux densities of a sample of 82 local gas-rich galaxies, including 70 "dwarf" galaxies (M_*_<10^9^M_{sun}_), from the Local Volume HI Survey (LVHIS), which is close to volume limited. It is found that LVHIS galaxies hold a tight linear FIR-radio correlation (FRC) over four orders of magnitude. However, for detected galaxies only, a trend of larger FIR-to-radio ratio with decreasing flux density is observed. We estimate the star formation rate by combining UV and mid-IR data using empirical calibration. It is confirmed that both FIR and radio emission are strongly connected with star formation but with significant non-linearity. Dwarf galaxies are found radiation deficient in both bands, when normalized by star formation rate. It urges a "conspiracy" to keep the FIR-to-radio ratio generally constant. By using partial correlation coefficient in Pearson definition, we identify the key galaxy properties associated with the FIR and radio deficiency. Some major factors, such as stellar mass surface density, will cancel out when taking the ratio between FIR and radio fluxes. The remaining factors, such as HI-to-stellar mass ratio and galaxy size, are expected to cancel each other due to the distribution of galaxies in the parameter space. Such cancellation is probably responsible for the "conspiracy" to keep the FRC alive.
- ID:
- ivo://CDS.VizieR/J/MNRAS/471/267
- Title:
- Ly{alpha} fluxes of HDFS 2.91<z<6.64 sources
- Short Name:
- J/MNRAS/471/267
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first estimate of the Ly{alpha} luminosity function using blind spectroscopy from the Multi Unit Spectroscopic Explorer, MUSE, in the Hubble Deep Field-South. Using automatic source-detection software, we assemble a homogeneously detected sample of 59 Ly{alpha} emitters covering a flux range of -18.0<log_10_(F)<-16.3(erg/s/cm2), corresponding to luminosities of 41.4<log_10_(L)<42.8(erg/s). As recent studies have shown, Ly{alpha} fluxes can be underestimated by a factor of 2 or more via traditional methods, and so we undertake a careful assessment of each object's Ly{alpha} flux using a curve-of-growth analysis to account for extended emission. We describe our self-consistent method for determining the completeness of the sample, and present an estimate of the global Ly {alpha} luminosity function between redshifts 2.91<z<6.64 using the 1/V_max_ estimator. We find that the luminosity function is higher than many number densities reported in the literature by a factor of 2-3, although our result is consistent at the 1{sigma} level with most of these studies. Our observed luminosity function is also in good agreement with predictions from semi-analytic models, and shows no evidence for strong evolution between the high- and low-redshift halves of the data. We demonstrate that one's approach to Ly{alpha} flux estimation does alter the observed luminosity function, and caution that accurate flux assessments will be crucial in measurements of the faint-end slope. This is a pilot study for the Ly{alpha} luminosity function in the MUSE deep-fields, to be built on with data from the Hubble Ultra Deep Field that will increase the size of our sample by almost a factor of 10.
- ID:
- ivo://CDS.VizieR/J/MNRAS/391/1457
- Title:
- Lyman{alpha} forest in QSO pairs
- Short Name:
- J/MNRAS/391/1457
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We look for signs of the HI transverse proximity effect in the spectra of 130 quasi-stellar object (QSO) pairs, most with transverse separations in the plane of the sky of 0.1-3Mpc at z~2.2. We expected to see a decrease in Ly{alpha} forest HI absorption in the spectrum of background QSOs near the position of foreground QSOs. Instead, we see no change in the absorption in front of the foreground QSOs, and we see evidence for a 50 per cent increase in the absorption out to 6Mpc behind the foreground QSOs. Further, we see no change in the HI absorption along the line-of-sight to the foreground QSOs, the normal line-of-sight proximity effect. We may account for the lack of change in the HI absorption if the effect of extra ultraviolet photons is cancelled by higher gas density around QSOs. If so, the increase in absorption behind the QSOs then suggests that the higher gas density there is not cancelled by the UV radiation from the QSOs. We can explain our observations if QSOs have had their current UV luminosities for less than approximately a million years, a time-scale that has been suggested for accretion disc instabilities and gas depletion.
- ID:
- ivo://CDS.VizieR/J/A+A/596/A86
- Title:
- Lynx-Cancer void sample galaxies HI data
- Short Name:
- J/A+A/596/A86
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Void population consists mainly of late-type and low surface brightness (LSB) dwarf galaxies, whose atomic hydrogen is the main component of their baryonic matter. Therefore observations of void galaxy HI are mandatory to understand both their evolution and dynamics. Our aim was to obtain integrated HI parameters for a fainter part of the nearby Lynx-Cancer void galaxy sample (total of 45 objects) with the Nancay Radio Telescope (NRT) and to conduct the comparative analysis of the whole 103 void galaxies with known HI data with a sample of similar galaxies residing in denser environments of the Local Volume. For HI observations we used the NRT with its sensitive antenna/receiver system FORT and standard processing. The comparison of the void and "control" samples on the parameter M(HI)/L_B_ is conducted with the non-parametric method "The 2x2 Contingency Table test". We obtained new HI data for about 40% of the Lynx-Cancer galaxy sample. Along with data from the literature, we use for further analysis data for 103 void objects. The proxy of the evolutional parameter M(HI)/L_B_ of the void sample is compared with that of 82 galaxies of morphological types 8-10 residing in the Local Volume groups and aggregates. At the confidence level of P=0.988, we conclude that for the same luminosity, these void galaxies are systematically gas-richer, in average by ~39%. This result is consistent with the authors' earlier conclusion on the smaller gas metallicities and evidences for the slower low-mass galaxy evolution in voids.
- ID:
- ivo://CDS.VizieR/J/other/PASAu/6.471
- Title:
- Magellanic Clouds bridge region HI profiles
- Short Name:
- J/other/PASAu/6.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Two hundred and seventeen HI profiles at positions approximately 1degree apart in the bridge region between the Small and Large Magellanic Clouds have been observed with a 15' arc beam. Diagrams of all the profiles, lists of column densities and average radial velocities are given, together with details of the extensive Gaussian analysis needed to account for the components. It is shown that the bridge region is most complex. (a) Two radial velocity (1) groups, +214 and +238km/s, represent the actual HI bridge between the two galaxies. (b) Three other components, at mean radial velocities of +155, +177 and +195km/s are seen to be integral parts of the SMC, stretching east to RA~04h. (c) A further three components in groups at mean radial Velocities +253, +272 and +293km/s appear to be extensions of HI from the main body of the LMC. Nine sets of five closely spaced observations in the lower Magellanic Stream and in the bridge region at high sensitivity supply further information about the region.
- ID:
- ivo://CDS.VizieR/VII/198
- Title:
- Mark III Catalog of Galaxy Peculiar Velocities
- Short Name:
- VII/198
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Tully-Fisher and Dn-sigma distances, radial velocities, and associated catalog and observational data for the spiral, irregular, and elliptical galaxies that comprise the Mark 3 catalog are given in 5 different kinds of tables for seven separate data sets. Users interested only in the resulting distances need use only the files listed in sections 3 (Grouped spiral distance files), 4 (Elliptical galaxy distance files), and 5 (Comparison of galaxy distances).
