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511. Low-redshift clusters in the SAMI Pilot Survey
ID:
ivo://CDS.VizieR/J/MNRAS/451/2723
Title:
Low-redshift clusters in the SAMI Pilot Survey
Short Name:
J/MNRAS/451/2723
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using new integral field observations of 106 galaxies in three nearby clusters, we investigate how the intrinsic scatter of the Fundamental Plane depends on the way in which the velocity dispersion and effective radius are measured. Our spatially resolved spectroscopy, combined with a cluster sample with negligible relative distance errors, allows us to derive a Fundamental Plane with minimal systematic uncertainties. From the apertures we tested, we find that velocity dispersions measured within a circular aperture with radius equal to one effective radius minimizes the intrinsic scatter of the Fundamental Plane. Using simple yet powerful Jeans dynamical models, we determine dynamical masses for our galaxies. Replacing luminosity in the Fundamental Plane with dynamical mass, we demonstrate that the resulting Mass Plane has further reduced scatter, consistent with zero intrinsic scatter. Using these dynamical models, we also find evidence for a possibly non-linear relationship between dynamical mass-to-light ratio and velocity dispersion.
512. LRG catalog
ID:
ivo://CDS.VizieR/J/MNRAS/380/1608
Title:
LRG catalog
Short Name:
J/MNRAS/380/1608
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this work I discuss the necessary steps for deriving photometric redshifts for luminous red galaxies (LRGs) and galaxy clusters through simple empirical methods. The data used are from the Sloan Digital Sky Survey (SDSS). I show that with three bands only (gri) it is possible to achieve results as accurate as the ones obtained by other techniques, generally based on more filters. In particular, the use of the (g-i) colour helps improving the final redshifts (especially for clusters), as this colour monotonically increases up to z~0.8. For the LRGs I generate a catalogue of ~1.5 million objects at z<0.70. The accuracy of this catalogue is sigma=0.027 for z<=0.55 and sigma=0.049 for 0.55<z<=0.70. The photometric redshift technique employed for clusters is independent of a cluster selection algorithm. Thus, it can be applied to systems selected by any method or wavelength, as long as the proper optical photometry is available. When comparing the redshift listed in literature to the photometric estimate, the accuracy achieved for clusters is sigma=0.024 for z<=0.30 and sigma=0.037 for 0.30<z<=0.55. However, when considering the spectroscopic redshift as the mean value of SDSS galaxies on each cluster region, the accuracy is at the same level as found by other authors: sigma=0.011 for z<=0.30 and sigma=0.016 for 0.30<z<=0.55. The photometric redshift relation derived here is applied to thousands of cluster candidates selected elsewhere. I have also used galaxy photometric redshifts available in SDSS to identify groups in redshift space and then compare the redshift peak of the nearest group to each cluster redshift. This procedure provides an alternative approach for cluster selection, especially at high redshifts, as the cluster red sequence may be poorly defined.
513. LSB galaxies in near-infrared. I.
ID:
ivo://CDS.VizieR/J/A+A/405/99
Title:
LSB galaxies in near-infrared. I.
Short Name:
J/A+A/405/99
Date:
21 Oct 2021
Publisher:
CDS
Description:
A sample of about 3800 Low Surface Brightness (LSB) galaxies was selected using the all-sky near-infrared (J, H and Ks-band) 2MASS survey. The selected objects have a mean central surface brightness within a 5" radius around their centre fainter than 18mag/arcsec^2^ in the Ks band, making them the lowest surface brightness galaxies detected by 2MASS. A description is given of the relevant properties of the 2MASS survey and the LSB galaxy selection procedure, as well as of basic photometric properties of the selected objects. The latter properties are compared to those of other samples of galaxies, of both LSBs and "classical'' high surface brightness (HSB) objects, which were selected in the optical. The 2MASS LSBs have a B_Tc_-K_T_ colour colour which is on average 0.9mag bluer than that of HSBs from the NGC. The 2MASS sample does not appear to contain a significant population of red objects.
514. LSB galaxies in near-infrared. II.
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.
515. LSB galaxies in near-infrared. III.
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.
516. LSBG catalogue
ID:
ivo://CDS.VizieR/J/MNRAS/304/297
Title:
LSBG catalogue
Short Name:
J/MNRAS/304/297
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have developed an automatic technique to search for low-surface-brightness (LSB) galaxies in the local Universe (v<=5000km/s) using the automated plate measuring (APM) scan data of UK Schmidt photographic plates. We optimized our technique and selection criteria by surveying the known LSB galaxies in the Fornax cluster. Plate-to-plate magnitude calibrations were carried out using independent CCD sequences. The galaxies we detected are brighter than 20Bmag, have scalesizes greater than 3arcsec and a central surface brightness fainter than 22.5mag/arcsec^2^. In total 2435 LSB galaxies were detected over a total area of 2187deg^2^. The survey covers the Fornax cluster, NGC 1400, Sculptor and Dorado groups and the field between. We detect on average 32 LSB galaxies per 5.8{deg}x5.8{deg} field. We have estimated the background (v>5000km/s) contamination in three ways: by numerical modelling, using a limited redshift sample and comparing our Fornax data with those of Ferguson. The results indicate a contamination of about 19 galaxies per field.
517. LSBG HI and optical properties
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.
518. Ly{alpha}-[CII] velocity offsets in MS galaxies
ID:
ivo://CDS.VizieR/J/A+A/643/A6
Title:
Ly{alpha}-[CII] velocity offsets in MS galaxies
Short Name:
J/A+A/643/A6
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Lyman-{alpha} line in the ultraviolet (UV) and the [CII] line in the far-infrared (FIR) are widely used tools to identify galaxies in the early Universe and to obtain insights into interstellar medium (ISM) properties in high-redshift galaxies. By combining data obtained with ALMA in band 7 at ~320GHz as part of the ALMA Large Program to INvestigate [CII] at Early Times (ALPINE) with spectroscopic data from DEIMOS at the Keck Observatory, VIMOS and FORS2 at the Very Large Telescope, we assembled a unique sample of 53 main-sequence star-forming galaxies at 4.4<z<6 in which we detect both the Lyman-{alpha} line in the UV and the [CII] line in the FIR. The goal of this paper is to constrain the properties of the Ly{alpha} emission in these galaxies in relation to other properties of the ISM. We used [CII], observed with ALMA, as a tracer of the systemic velocity of the galaxies, and we exploited the available optical spectroscopy to obtain the Ly{alpha}-[CII] and ISM-[CII] velocity offsets. We find that 90% of the selected objects have Ly{alpha}-[CII] velocity offsets in the range 0<{Delta}v_Ly{alpha}-[CII]_<400km/s, in line with the few measurements available so far in the early Universe, and significantly smaller than those observed at lower redshifts. At the same time, we observe ISM-[CII] offsets in the range -500<{Delta}v_ISM-[CII]_<0km/s, in line with values at all redshifts, which we interpret as evidence for outflows in these galaxies. We find significant anticorrelations between {Delta}v_Ly{alpha}-[CII]_ and the Ly{alpha} rest-frame equivalent width EW_0_(Ly{alpha}) (or equivalently, the Ly{alpha} escape fraction f_esc_(Ly{alpha})): galaxies that show smaller {Delta}v_Ly{alpha}-[CII]_ have larger EW_0_(Ly{alpha}) and f_esc_(Ly{alpha}). We interpret these results in the framework of available models for the radiative transfer of Ly{alpha} photons. According to the models, the escape of Ly{alpha} photons would be favored in galaxies with high outflow velocities, producing large EW_0_(Ly{alpha}) and small {Delta}v_Ly{alpha}-[CII]_, in agreement with our observations. The uniform shell model would also predict that the Ly{alpha} escape in galaxies with slow outflows (0<v_out_<300km/s) is mainly determined by the neutral hydrogen column density (NHI) along the line of sight, while the alternative model by Steidel et al. (2010ApJ...717..289S) would more highly favor a combination of NHI at the systemic velocity and covering fraction as driver of the Ly{alpha} escape. We suggest that the increase in Ly{alpha} escape that is observed in the literature between z~2 and z~6 is not due to a higher incidence of fast outflows at high redshift, but rather to a decrease in average NHI along the line of sight, or alternatively, a decrease in HI covering fraction.
519. Lyman break galaxies at redshift z~3
ID:
ivo://CDS.VizieR/J/ApJ/592/728
Title:
Lyman break galaxies at redshift z~3
Short Name:
J/ApJ/592/728
Date:
04 Dec 2021
Publisher:
CDS
Description:
We present the basic data for a large ground-based spectroscopic survey for z~3 Lyman break galaxies (LBGs), photometrically selected using rest-UV colors from very deep images in 17 high Galactic latitude fields. The total survey covers an area of 0.38deg^2^ and includes 2347 photometrically selected candidate LBGs to an apparent {R}_AB_ magnitude limit of 25.5. Approximately half of these objects have been observed spectroscopically using the Keck telescopes, yielding 940 redshifts with <z>=2.96+/-0.29. We discuss the images, photometry, target selection, and spectroscopic program in some detail and present catalogs of the photometric and spectroscopic data, made available in electronic form. We discuss the general utility of conducting nearly volume-limited redshift surveys in prescribed redshift intervals using judicious application of photometric preselection.
520. Lyman-break galaxies (LBG) in the HUDF
ID:
ivo://CDS.VizieR/J/ApJ/703/2033
Title:
Lyman-break galaxies (LBG) in the HUDF
Short Name:
J/ApJ/703/2033
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a sample of 407 z~3 Lyman break galaxies (LBGs) to a limiting isophotal u-band magnitude of 27.6mag in the Hubble Ultra Deep Field. The LBGs are selected using a combination of photometric redshifts and the u-band drop-out technique enabled by the introduction of an extremely deep u-band image obtained with the Keck I telescope and the blue channel of the Low Resolution Imaging Spectrometer. The Keck u-band image, totaling 9hr of integration time, has a 1{sigma} depth of 30.7mag/arcsec^2^, making it one of the most sensitive u-band images ever obtained. The u-band image also substantially improves the accuracy of photometric redshift measurements of ~50% of the z~3 LBGs, significantly reducing the traditional degeneracy of colors between z~3 and z~0.2 galaxies.

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