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1661. g'i' photometry in 5 isolated elliptical galaxies
ID:
ivo://CDS.VizieR/J/A+A/577/A59
Title:
g'i' photometry in 5 isolated elliptical galaxies
Short Name:
J/A+A/577/A59
Date:
21 Oct 2021
Publisher:
CDS
Description:
As tracers of star formation, galaxy assembly and mass distribution, globular clusters have provided important clues to our understanding of early-type galaxies. But their study has been mostly constrained to galaxy groups and clusters where early-type galaxies dominate, leaving the properties of the globular cluster systems (GCSs) of isolated ellipticals as a mostly uncharted territory. We present Gemini-South/GMOS g'i' observations of five isolated elliptical galaxies: NGC 3962, NGC 2865, IC 4889, NGC 2271 and NGC 4240. Photometry of their GCSs reveals clear color bimodality in three of them, remaining inconclusive for the other two. All the studied GCSs are rather poor with a mean specific frequency S_N_~1.5, independently of the parent galaxy luminosity. Considering also previous work, it is clear that bimodality and especially the presence of a significant, even dominant, population of blue clusters occurs at even the most isolated systems, casting doubts on a possible accreted origin of metal-poor clusters as suggested by some models. Additionally, we discuss the possible existence of ultra-compact dwarfs around the isolated elliptical NGC 3962.
1662. gi photometry of Bootes I
ID:
ivo://CDS.VizieR/J/MNRAS/461/3702
Title:
gi photometry of Bootes I
Short Name:
J/MNRAS/461/3702
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present deep stellar photometry of the Bootes I dwarf spheroidal galaxy in g- and i-band filters, taken with the Dark Energy Camera at Cerro Tololo in Chile. Our analysis reveals a large, extended region of stellar substructure surrounding the dwarf, as well as a distinct overdensity encroaching on its tidal radius. A radial profile of the Bootes I stellar distribution shows a break radius indicating the presence of extra-tidal stars. These observations strongly suggest that Bootes I is experiencing tidal disruption, although not as extreme as that exhibited by the Hercules dwarf spheroidal. Combined with revised velocity dispersion measurements from the literature, we see evidence suggesting the need to review previous theoretical models of the Bootes I dwarf spheroidal galaxy.
1663. gi photometry of 14 LMC star clusters
ID:
ivo://CDS.VizieR/J/MNRAS/444/1425
Title:
gi photometry of 14 LMC star clusters
Short Name:
J/MNRAS/444/1425
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present Gemini South GMOS g, i photometry of 14 intermediate-age Large Magellanic Cloud (LMC) star clusters, namely: NGC 2155, 2161, 2162, 2173, 2203, 2209, 2213, 2231, 2249, Hodge 6, SL 244, 505, 674, and 769, as part of a continuing project to investigate the extended main-sequence turn-off (EMSTO) phenomenon. Extensive artificial star tests were made over the observed field of view. These tests reveal the observed behaviour of photometric errors with magnitude and crowding. The cluster stellar density radial profiles were traced from star counts over the extent of the observed field. We adopt cluster radii and build colour-magnitude diagrams (CMDs) with cluster features clearly identified. We used the cluster (g, g-i) CMDs to estimate ages from the matching of theoretical isochrones. The studied LMC clusters are confirmed to be intermediate-age clusters, which range in age 9.10<log(t)<9.60. NGC 2162 and NGC 2249 look like new EMSTO candidates, in addition to NGC 2209, on the basis of having dual red clumps.
1664. gi photometry of Sextans dSph galaxy stars
ID:
ivo://CDS.VizieR/J/MNRAS/460/30
Title:
gi photometry of Sextans dSph galaxy stars
Short Name:
J/MNRAS/460/30
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present wide-field g- and i-band stellar photometry of the Sextans dwarf spheroidal galaxy and its surrounding area out to four times its half-light radius (r_h_=695pc), based on images obtained with the Dark Energy Camera at the 4-m Blanco telescope at CTIO. We find clear evidence of stellar substructure associated with the galaxy, extending to a distance of 82-arcmin (2kpc) from its centre. We perform a statistical analysis of the overdensities and find three distinct features, as well as an extended halo-like structure, to be significant at the 99.7 per cent confidence level or higher. Unlike the extremely elongated and extended substructures surrounding the Hercules dwarf spheroidal galaxy, the overdensities seen around Sextans are distributed evenly about its centre, and do not appear to form noticeable tidal tails. Fitting a King model to the radial distribution of Sextans stars yields a tidal radius r_t_=83.2-arcmin+/-7.1 arcmin (2.08+/-0.18kpc), which implies the majority of detected substructure is gravitationally bound to the galaxy. This finding suggests that Sextans is not undergoing significant tidal disruption from the Milky Way, supporting the scenario in which the orbit of Sextans has a low eccentricity.
1665. GIRAFFE Inner Bulge Survey (GIBS). II.
ID:
ivo://CDS.VizieR/J/A+A/584/A46
Title:
GIRAFFE Inner Bulge Survey (GIBS). II.
Short Name:
J/A+A/584/A46
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate metallicity and {alpha}-element abundance gradients along a Galactic longitude strip, at latitude b~-4{deg}, with the aim of providing observational constraints for the structure and origin of the Milky Way bulge. High-resolution (R~22500) spectra for 400 Kgiants, in four fields within -4.8{deg}<~b<~-3.4{deg} and -10{deg}<~l<~+10{deg}, were obtained within the GIRAFFE Inner Bulge Survey (GIBS) project. To this sample we added another ~400 stars in Baade's Window at (l,b)=(1{deg},-4{deg}), observed with the identical instrumental configuration: FLAMES GIRAFFE in Medusa mode with HR13 setup. All target stars lie within the red clump of the bulge colour-magnitude diagram, thus minimising contamination from the disc or halo stars. The spectroscopic stellar surface parameters were derived with an automatic method based on the GALA code, while the [Ca/Fe] and [Mg/Fe] abundances as a function of [Fe/H] were derived through a comparison with the synthetic spectra using MOOG. We constructed the metallicity distributions for the entire sample, and for each field individually, in order to investigate the presence of gradients or field-to-field variations in the shape of the distributions.
1666. GLADE catalog
ID:
ivo://CDS.VizieR/VII/275
Title:
GLADE catalog
Short Name:
VII/275
Date:
21 Oct 2021
Publisher:
CDS
Description:
We are introducing a value-added full-sky galaxy catalog with high completeness for identifying gravitational wave (GW) sources in order to support future electromagnetic (EM) follow-up projects of the LIGO/Virgo Collaboration. The catalog GLADE (Galaxy List for the Advanced Detector Era) has been constructed (combined and matched) from four existing galaxy catalogs: GWGC, 2MPZ, 2MASS XSC and HyperLEDA. It contains 1918147 galaxies, which is two orders of magnitude greater than the number of galaxies in the GWGC catalog alone (53312), which is currently in use by the collaboration. Furthermore we considered it as a crucial requirement towards the catalog to contain B-band magnitudes and distances for all entries. Therefore we have associated these properties for 548876 2MASS galaxies which lacked them with a regression algorithm teached on a subsample of the 2MPZ catalog. Our catalog is complete to 73Mpc and even at 300Mpc has a relatively high completeness (53%). Naturally, our catalog could be used in a broad range of various astrophysical projects besides EM follow-up efforts.We are introducing a value-added full-sky galaxy catalog with high completeness for identifying gravitational wave (GW) sources in order to support future electromagnetic (EM) follow-up projects of the LIGO/Virgo Collaboration. The catalog has been constructed (combined and matched) from four existing galaxy catalogs: GWGC, 2MPZ, 2MASS XSC and HyperLEDA. It contains 1918147 galaxies, which is two orders of magnitude greater than the number of galaxies in the GWGC catalog alone (53312), which is currently in use by the collaboration. Furthermore we considered it as a crucial requirement towards the catalog to contain B-band magnitudes and distances for all entries. Therefore we have associated these properties for 548,876 2MASS galaxies which lacked them with a regression algorithm teached on a subsample of the 2MPZ catalog. Our catalog is complete to 73 Mpc and even at 300 Mpc has a relatively high completeness (53%). Naturally, our catalog could be used in a broad range of various astrophysical projects besides EM follow-up efforts. For a brief overview of the GLADE project, check out the talk slides (http://aquarius.elte.hu/glade/GLADE_GDalya_LVC2015September.pdf) presented at the 2015 September LIGO-Virgo Collaboration Meeting in Budapest, Hungary. If you have any questions or suggestions about the catalog, please send us an email: dalyag@caesar.elte.hu
1667. GLADE v2.3 catalog
ID:
ivo://CDS.VizieR/VII/281
Title:
GLADE v2.3 catalog
Short Name:
VII/281
Date:
21 Oct 2021
Publisher:
CDS
Description:
We introduce a value-added full-sky catalogue of galaxies, named as Galaxy List for the Advanced Detector Era, or GLADE. The purpose of this catalogue is to (i) help identifications of host candidates for gravitational-wave events, (ii) support target selections for electromagnetic follow-up observations of gravitational-wave candidates, (iii) provide input data on the matter distribution of the local Universe for astrophysical or cosmological simulations, and (iv) help identifications of host candidates for poorly localized electromagnetic transients, such as gamma-ray bursts observed with the InterPlanetary Network. Both being potential hosts of astrophysical sources of gravitational waves, GLADE includes inactive and active galaxies as well. GLADE was constructed by cross-matching and combining data from five separate (but not independent) astronomical catalogues: GWGC, 2MPZ, 2MASS XSC, HyperLEDA, and SDSS-DR12Q. GLADE is complete up to d_L_=37^+3^_-4_Mpc in terms of the cumulative B-band luminosity of galaxies within luminosity distance dL, and contains all of the brightest galaxies giving half of the total B-band luminosity up to d_L_=91Mpc. As B-band luminosity is expected to be a tracer of binary neutron star mergers (currently the prime targets of joint GW+EM detections), our completeness measures can be used as estimations of completeness for containing all binary neutron star merger hosts in the local Universe.
1668. GLASS. IV. Lensing cluster Abell 2744
ID:
ivo://CDS.VizieR/J/ApJ/811/29
Title:
GLASS. IV. Lensing cluster Abell 2744
Short Name:
J/ApJ/811/29
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a strong and weak lensing reconstruction of the massive cluster Abell 2744, the first cluster for which deep Hubble Frontier Fields (HFF) images and spectroscopy from the Grism Lens-Amplified Survey from Space (GLASS) are available. By performing a targeted search for emission lines in multiply imaged sources using the GLASS spectra, we obtain five high-confidence spectroscopic redshifts and two tentative ones. We confirm one strongly lensed system by detecting the same emission lines in all three multiple images. We also search for additional line emitters blindly and use the full GLASS spectroscopic catalog to test reliability of photometric redshifts for faint line emitters. We see a reasonable agreement between our photometric and spectroscopic redshift measurements, when including nebular emission in photometric redshift estimations. We introduce a stringent procedure to identify only secure multiple image sets based on colors, morphology, and spectroscopy. By combining 7 multiple image systems with secure spectroscopic redshifts (at 5 distinct redshift planes) with 18 multiple image systems with secure photometric redshifts, we reconstruct the gravitational potential of the cluster pixellated on an adaptive grid, using a total of 72 images. The resulting mass map is compared with a stellar mass map obtained from the deep Spitzer Frontier Fields data to study the relative distribution of stars and dark matter in the cluster. We find that the stellar to total mass ratio varies substantially across the cluster field, suggesting that stars do not trace exactly the total mass in this interacting system. The maps of convergence, shear, and magnification are made available in the standard HFF format.
1669. GLASS. IX. Structural param. from HFF & GLASS
ID:
ivo://CDS.VizieR/J/ApJ/835/254
Title:
GLASS. IX. Structural param. from HFF & GLASS
Short Name:
J/ApJ/835/254
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using deep Hubble Frontier Fields imaging and slitless spectroscopy from the Grism Survey from Space, we study 2200 cluster and 1748 field galaxies at 0.2<=z<=0.7 to determine the impact of environment on galaxy size and structure at stellar masses logM_*_/M_{sun}_>7.8, an unprecedented limit at these redshifts. Based on simple assumptions-r_e_=f(M_*_)-we find no significant differences in half-light radii (r_e_) between equal-mass cluster or field systems. More complex analyses --r_e_=f(M_*_,U-V,n,z,{Sigma})-- reveal local density ({Sigma}) to induce only a 7%+/-3% (95% confidence) reduction in r_e_ beyond what can be accounted for by U-V color, Sersic index (n), and redshift (z) effects. Almost any size difference between galaxies in high- and low-density regions is thus attributable to their different distributions in properties other than environment. Indeed, we find a clear color-r_e_ correlation in low-mass passive cluster galaxies (logM_*_/M_{sun}_<9.8) such that bluer systems have larger radii, with the bluest having sizes consistent with equal-mass star-forming galaxies. We take this as evidence that large-r_e_ low-mass passive cluster galaxies are recently acquired systems that have been environmentally quenched without significant structural transformation (e.g., by ram pressure stripping or starvation). Conversely, ~20% of small-r_e_ low-mass passive cluster galaxies appear to have been in place since z>~3. Given the consistency of the small-r_e_ galaxies' stellar surface densities (and even colors) with those of systems more than ten times as massive, our findings suggest that clusters mark places where galaxy evolution is accelerated for an ancient base population spanning most masses, with late-time additions quenched by environment-specific mechanisms mainly restricted to the lowest masses.
1670. GLASS. VII. H{alpha} maps
ID:
ivo://CDS.VizieR/J/ApJ/833/178
Title:
GLASS. VII. H{alpha} maps
Short Name:
J/ApJ/833/178
Date:
21 Oct 2021
Publisher:
CDS
Description:
Exploiting the slitless spectroscopy taken as part of the Grism Lens-Amplified Survey from Space (GLASS), we present an extended analysis of the spatial distribution of star formation in 76 galaxies in 10 clusters at 0.3<z<0.7. We use 85 foreground and background galaxies in the same redshift range as a field sample. The samples are well matched in stellar mass (10^8^-10^11^M_{sun}_) and star formation rate (0.5-50M_{sun}_/yr). We visually classify galaxies in terms of broad band morphology, H{alpha} morphology, and likely physical process acting on the galaxy. Most H{alpha} emitters have a spiral morphology (41%+/-8% in clusters, 51%+/-8% in the field), followed by mergers/interactions (28%+/-8%, 31%+/-7%, respectively) and early-type galaxies (remarkably as high as 29%+/-8% in clusters and 15%+/-6% in the field). A diversity of H{alpha} morphologies is detected, suggesting a diversity of physical processes. In clusters, 30%+/-8% of the galaxies present a regular morphology, mostly consistent with star formation diffused uniformly across the stellar population (mostly in the disk component, when present). The second most common morphology (28%+/-8%) is asymmetric/jellyfish, consistent with ram-pressure stripping or other non-gravitational processes in 18%+/-8% of the cases. Ram-pressure stripping appears significantly less prominent in the field (2%+/-2%), where the most common morphology/mechanism appears to be consistent with minor gas-rich mergers or clump accretion. This work demonstrates that while environment-specific mechanisms affect galaxy evolution at this redshift, they are diverse and their effects are subtle. A full understanding of this complexity requires larger samples and detailed and spatially resolved physical models.