- 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.
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- 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).
- ID:
- ivo://CDS.VizieR/J/AJ/152/157
- Title:
- Mass models for 175 disk galaxies with SPARC
- Short Name:
- J/AJ/152/157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We introduce SPARC (Spitzer Photometry and Accurate Rotation Curves): a sample of 175 nearby galaxies with new surface photometry at 3.6{mu}m and high-quality rotation curves from previous HI/H{alpha} studies. SPARC spans a broad range of morphologies (S0 to Irr), luminosities (~5dex), and surface brightnesses (~4dex). We derive [3.6] surface photometry and study structural relations of stellar and gas disks. We find that both the stellar mass-HI mass relation and the stellar radius-HI radius relation have significant intrinsic scatter, while the HI mass-radius relation is extremely tight. We build detailed mass models and quantify the ratio of baryonic to observed velocity (V_bar_/V_obs_) for different characteristic radii and values of the stellar mass-to-light ratio ({Upsilon}_*_) at [3.6]. Assuming {Upsilon}_*_{simeq}0.5M_{Sun}_/L_{Sun}_ (as suggested by stellar population models), we find that (i) the gas fraction linearly correlates with total luminosity; (ii) the transition from star-dominated to gas-dominated galaxies roughly corresponds to the transition from spiral galaxies to dwarf irregulars, in line with density wave theory; and (iii) V_bar_/V_obs_ varies with luminosity and surface brightness: high-mass, high-surface-brightness galaxies are nearly maximal, while low-mass, low-surface-brightness galaxies are submaximal. These basic properties are lost for low values of {Upsilon}_*_ {simeq}0.2M_{Sun}_/L_{Sun}_ as suggested by the DiskMass survey. The mean maximum-disk limit in bright galaxies is {Upsilon}_*_{simeq}0.7M_{Sun}_/L_{Sun}_ at [3.6]. The SPARC data are publicly available and represent an ideal test bed for models of galaxy formation.
- ID:
- ivo://CDS.VizieR/J/A+A/522/A3
- Title:
- M33 CO(2-1) and HI integrated intensity maps
- Short Name:
- J/A+A/522/A3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-resolution large-scale observations of the molecular and atomic gas in the Local Group galaxy M 33. The observations were carried out using the HEterodyne Receiver Array (HERA) at the 30m IRAM telescope in the CO(2-1) line, achieving a resolution of 12"x2.6km/s, enabling individual giant molecular clouds (GMCs) to be resolved. The observed region is 650 square arcminutes mainly along the major axis and out to a radius of 8.5kpc, and covers entirely the 2'x40' radial strip observed with the HIFI and PACS Spectrometers as part of the HERM33ES Herschel key program. The achieved sensitivity in main-beam temperature is 20-50mK at 2.6km/s velocity resolution. The CO(2-1) luminosity of the observed region is 1.7+/-0.1x10^7^K.km/s.pc^2^ and is estimated to be 2.8+/-0.3x10^7^K.km/s.pc^2^ for the entire galaxy, corresponding to H_2_ masses of 1.9x10^8^ and 3.3x10^8^ respectively (including He), calculated with N(H_2_)/I_CO_(1-0) twice the Galactic value due to the half-solar metallicity of M 33. The HI 21cm VLA archive observations were reduced, and the mosaic was imaged and cleaned using the multi-scale task in the CASA software package, yielding a series of datacube with resolutions ranging from 5" to 25". The HI mass within a radius of 8.5kpc is estimated to be 1.4x10^9^. The azimuthally averaged CO surface brightness decreases exponentially with a scale length of 1.9+/-0.1kpc whereas the atomicgas surface density is constant at {Sigma}_HI_=6+/-2pc^-2^ deprojected to face-on. For an (H_2_)/I_CO_(1-0) conversion factor twice that of the Milky Way, the central kiloparsec H2 surface density is {Sigma}_HI_=8.5+/-0.2pc^-2^. The star formation rate per unit moecular gas (SF efficiency, the rate of transformation of molecular gas into stars), as traced by the ratio of CO to H{alpha} and FIR brightness, is constant with radus. The SFE, with a N(H2)/I_CO_(1-0) factor twice galactic, appears 2-4 times greater than for large spiral galaxies. A morphological comparison of molecular and atomic gas with tracers of star formation is presented showing good agreement between these maps both in terms of peaks and holes. A few exceptions are noted. Several spectra, including those of a molecular cloud situated more than 8kpc from the galaxy center, are presented.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A173
- Title:
- MeerKAT 21-cm HI imaging of Abell 2626
- Short Name:
- J/A+A/654/A173
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The morphology-density relation manifests the environmental dependence of the formation and evolution of galaxies as they continuously migrate through the cosmic web to ever denser environments. As gas-rich galaxies traverse the outskirts and inner regions of galaxy clusters, they experience sudden and radical changes in their gas content and star formation activity. The goal of this work is to gain an HI perspective on gas depletion mechanisms acting on galaxies and galaxy groups that are being accreted by a moderately massive galaxy cluster. We aim to study the relative importance and efficiency of processes such as ram-pressure stripping and tidal interactions as well as their dependency on the local and global environment of galaxies in the cluster core and in its surroundings. We have conducted a blind radio continuum and Hi spectral line imaging survey with the MeerKAT radio telescope of a 2"x2" area centred on the galaxy cluster Abell 2626. We have used the CARAcal pipeline to reduce the data, SoFiA to detect sources within the Hi data cube, and GIPSY to construct spatially resolved information on the Hi morphologies and kinematics of the Hi detected galaxies. We have detected HI in 219 galaxies with optical counterparts within the entire surveyed volume. We present the HI properties of each of the detected galaxies as a data catalogue and as an atlas page for each galaxy, including HI column-density maps, velocity fields, position-velocity diagrams, and global HI profiles. These data will also be used for case studies of identified 'jellyfish' galaxies and galaxy population studies by means of morphological classification of the direct HI detections as well as using the HI stacking technique.
