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2421. 4 nearby galaxies velocities & line-strengths
ID:
ivo://CDS.VizieR/J/A+A/428/877
Title:
4 nearby galaxies velocities & line-strengths
Short Name:
J/A+A/428/877
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present observations of four nearby early-type galaxies previously known (Rest et al., 2001AJ....121.2431R) to have nuclear stellar disks using two instruments on-board the Hubble Space Telescope. We observed NGC 4128, NGC 4612, and NGC 5308 with the Wide Field Planetary Camera 2, and the same three galaxies, plus NGC 4570, with the Space Telescope Imaging Spectrograph. We have detected a red nucleus in NGC 4128, a blue nucleus in NGC 4621, and a blue disk in NGC 5308. Additionally, we have discovered a blue disk-like feature with position angle ~15{deg} from the major axis in NGC 4621. In NGC 5308 there is evidence for a blue region along the minor axis. We discovered a blue transient on the images of NGC 4128 at position 0.14" west and 0.32" north from the nucleus. The extracted kinematic profiles belong to two groups: fast (NGC 4570 and NGC 5308) and kinematically disturbed rotators (NGC 4128 and NGC 4621). We report the discovery of a kinematically decoupled core in NGC 4128. Galaxies have mostly old (10-14Gyr) stellar populations with large spread in metallicities (sub- to super-solar). We discuss the possible formation scenarios, including bar-driven secular evolution and the influence of mergers, which can explain the observed color and kinematic features.
2422. Nearby galaxy clusters X-ray point sources
ID:
ivo://CDS.VizieR/J/MNRAS/471/4990
Title:
Nearby galaxy clusters X-ray point sources
Short Name:
J/MNRAS/471/4990
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this work, we studied 10 nearby (z<=0.038) galaxy clusters to understand possible interactions between hot plasma and member galaxies. A multi-band source detection was applied to detect point-like structures within the intra-cluster medium. We examined the spectral properties of a total of 391 X-ray point sources within each cluster's potential well. log N versus log S was studied in the energy range 2-10 keV to measure X-ray overdensities. Optical overdensities were also calculated to solve suppression/triggering phenomena for nearby galaxy clusters. X-ray and optical flux/luminosity properties (X/O, L_X_/L_B_ and L_X_/L_K_) were investigated for optically identified member galaxies. The X-ray luminosities of our point sources were found to be faint [40.08<=log(L_X_)<=42.39erg/s]. The luminosity range of point sources reveals possible contributions to X-ray emission from low-luminosity active galactic nuclei, X-ray binaries and star formation. We estimated ~2 times higher X-ray overdensities from galaxies within galaxy clusters compared to fields. Our results demonstrate that optical overdensities are much higher than X-ray overdensities at a cluster's centre, whereas X-ray overdensities increase through the outskirts of clusters. We conclude that high pressure from a cluster's centre affects the balance of galaxies and they lose a significant amount of their fuel. As a result, the clustering process quenches the X-ray emission of the member galaxies. We also find evidence that the existence of X-ray bright sources within a cluster environment can be explained by two main phenomena: contributions from off-nuclear sources and/or active galactic nucleus (AGN) triggering caused by galaxy interactions rather than AGN fuelling.
2423. Nearby galaxy filaments with UV obs.
ID:
ivo://CDS.VizieR/J/ApJ/814/40
Title:
Nearby galaxy filaments with UV obs.
Short Name:
J/ApJ/814/40
Date:
21 Oct 2021
Publisher:
CDS
Description:
Simulations of the formation of large-scale structures predict that dark matter, low density highly ionized gas, and galaxies form 10 to 40Mpc scale filaments. These structures are easily recognized in the distribution of galaxies. Here we use Ly{alpha} absorption lines to study the gas in 30x6Mpc filament at cz~3500km/s, defined using a new catalog of nearby (cz<10000km/s) galaxies, which is complete down to a luminosity of about 0.05L_*_ for the region of space analyzed here. Using Hubble Space Telescope spectra of 24 active galactic nuclei, we sample the gas in this filament. All of our sightlines pass outside the virial radius of any known filament galaxy. Within 500kpc of the filament axis the detection rate is ~80%, but no detections are seen more than 2.1Mpc from the filament axis. The width of the Ly{alpha} lines correlates with filament impact parameter and the four BLAs in our sample occur within 400kpc of the filament axis, indicating increased temperature and/or turbulence. Comparing to simulations, we find that the recent Haardt & Madau extragalactic ionizing background predicts a factor of 3-5 too few ionizing photons. Using a more intense radiation field matches the hydrogen density profile within 2.1Mpc of the filament axis, but the simulations still overpredict the detection rate between 2.1 and 5Mpc from the axis. The baryonic mass inside filament galaxies is 1.4x10^13^M_{sun}_, while the mass of filament gas outside galaxy halos is found to be 5.2x10^13^M_{sun}_.
2424. Nearby galaxy perspective on dust evolution
ID:
ivo://CDS.VizieR/J/A+A/649/A18
Title:
Nearby galaxy perspective on dust evolution
Short Name:
J/A+A/649/A18
Date:
22 Feb 2022
Publisher:
CDS
Description:
The efficiency of the different processes responsible for the evolution of interstellar dust on the scale of a galaxy are, to date, very uncertain, spanning several orders of magnitude in the literature. Yet, precise knowledge of the grain properties is key to addressing numerous open questions about the physics of the interstellar medium and galaxy evolution. This article presents an empirical statistical study, aimed at quantifying the timescales of the main cosmic dust evolution processes as a function of the global properties of a galaxy. We have modelled a sample of ~800 nearby galaxies, spanning a wide range of metallicity, gas fraction, specific star formation rate and Hubble stage. We have derived the dust properties of each object from its spectral energy distribution. Throughout this paper, we have adopted a hierarchical Bayesian approach, resulting in a single large probability distribution of all the parameters of all the galaxies, to ensure the most rigorous interpretation of our data. We confirm the drastic evolution with metallicity of the dust-to-metal mass ratio (by two orders of magnitude), found by previous studies. We confirm the well-known evolution of the aromatic-feature-emitting grain mass fraction as a function of metallicity and interstellar radiation field intensity. Our data indicate the relation with metallicity is significantly stronger. Our results provide valuable constraints for simulations of galaxies. They imply that grain growth is the likely dust production mechanism in dusty high-redshift objects. We also emphasize the determinant role of local, low metallicity systems in order to address these questions.
2425. Nearby massive early-type galaxies from MATLAS
ID:
ivo://CDS.VizieR/J/MNRAS/498/2138
Title:
Nearby massive early-type galaxies from MATLAS
Short Name:
J/MNRAS/498/2138
Date:
12 Jan 2022 05:42:10
Publisher:
CDS
Description:
The morphology of galaxies gives essential constraints on the models of galaxy evolution. The morphology of the features in the low-surface-brightness (LSB) regions of galaxies has not been fully explored yet because of observational difficulties. Here we present the results of our visual inspections of very deep images of a large volume-limited sample of 177 nearby massive early-type galaxies from the MATLAS survey. The images reach a surface-brightness limit of 28.5-29mag/arcsec^2^ in the g' band. Using a dedicated navigation tool and questionnaire, we looked for structures at the outskirts of the galaxies such as tidal shells, streams, tails, disturbed outer isophotes, or peripheral star-forming discs, and simultaneously noted the presence of contaminating sources, such as Galactic cirrus. We also inspected internal substructures such as bars and dust lanes. We discuss the reliability of this visual classification investigating the variety of answers made by the participants. We present the incidence of these structures and the trends of the incidence with the mass of the host galaxy and the density of its environment. We find an incidence of shells, stream, and tails of approximately 15%, about the same for each category. For galaxies with masses over 10^11^M_{sun}_, the incidence of shells and streams increases about 1.7 times. We also note a strong unexpected anticorrelation of the incidence of Galactic cirrus with the environment density of the target galaxy. Correlations with other properties of the galaxies, and comparisons to model predictions, will be presented in future papers.
2426. Nearby Optical Galaxy (NOG) sample
ID:
ivo://CDS.VizieR/J/ApJ/543/178
Title:
Nearby Optical Galaxy (NOG) sample
Short Name:
J/ApJ/543/178
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper we describe the Nearby Optical Galaxy (NOG) sample, which is a complete, distance-limited (cz<=6000km/s) and magnitude-limited (B<=14) sample of ~7000 optical galaxies. The sample covers 2/3 (8.27sr) of the sky (|b|>20{deg}) and appears to have a good completeness in redshift (97%). We select the sample on the basis of homogenized corrected total blue magnitudes in order to minimize systematic effects in galaxy sampling. We identify the groups in this sample by means of both the hierarchical and the percolation "friends-of-friends" methods. The resulting catalogs of loose groups appear to be similar and are among the largest catalogs of groups currently available. Most of the NOG galaxies (~60%) are found to be members of galaxy pairs (~580 pairs for a total of ~15% of objects) or groups with at least three members (~500 groups for a total of ~45% of objects). About 40% of galaxies are left ungrouped (field galaxies). We illustrate the main features of the NOG galaxy distribution. Compared to previous optical and IRAS galaxy samples, the NOG provides a denser sampling of the galaxy distribution in the nearby universe. Given its large sky coverage, the identification of groups, and its high-density sampling, the NOG is suited to the analysis of the galaxy density field of the nearby universe, especially on small scales.
2427. Nearby poor clusters of galaxies catalog
ID:
ivo://CDS.VizieR/J/AJ/118/2014
Title:
Nearby poor clusters of galaxies catalog
Short Name:
J/AJ/118/2014
Date:
21 Oct 2021
Publisher:
CDS
Description:
A catalog of 732 optically selected, nearby poor clusters of galaxies covering the entire sky north of -3{deg} declination is presented. The poor clusters, called WBL clusters, were identified as concentrations of three or more galaxies with photographic magnitudes brighter than 15.7, possessing a galaxy surface overdensity of 10^4/3^. These criteria are consistent with those used in the identification of the original Yerkes poor clusters, and this new catalog substantially increases the sample size of such objects. These poor clusters cover the entire range of galaxy associations up to and including Abell clusters, systematically including poor and rich galaxy systems spanning over 3 orders of magnitude in the cluster mass function. As a result, this new catalog contains a greater diversity of richness and structures than other group catalogs, such as the Hickson and Yerkes catalogs. The information on individual galaxies includes redshifts and cross-references to other galaxy catalogs. The entries for the clusters include redshift (where available) and cross-references to other group and cluster catalogs.
2428. Nearby radio galaxies FUV to MIR properties
ID:
ivo://CDS.VizieR/J/A+A/581/A33
Title:
Nearby radio galaxies FUV to MIR properties
Short Name:
J/A+A/581/A33
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate whether the far-UV continuum of nearby radio galaxies is due solely to the parent galaxy that passively evolves, or if it reveals evidence for the presence of other star-forming or non-stellar components. If the UV excess is due to an additional radiation component, we compare this with other properties such as radio power, optical spectral type (e.g. high- and low-excitation galaxies), and the strength of the emission lines. We also discuss the possible correlation between the ultraviolet flux, IR properties, and the central black hole mass. We used a sample of low-luminosity B2 radio galaxies and a small sample of higher luminosity 3C radio galaxies at comparable redshift (z<0.2). Spectral energy distributions (SEDs) were constructed using a number of on-line databases that are freely available now: GALEX, SDSS, 2MASS, and WISE. These were compared with model SEDs of early-type galaxies with passively evolving stellar populations at various ages (typically 0.5-1.3x10^9^ years). We established whether a second component was needed to obtain a satisfactory fit with the observed overall SED. We introduce the parameter XUV, which measures the excess slope of the UV continuum between 4500 and 2000{AA} with respect to the UV radiation produced by the underlying old galaxy component. We find that the UV excess as measured by XUV is usually small or absent in low-luminosity (FR I) sources, but sets in abruptly at the transition radio power, above which we find mostly FRII sources. XUV behaves very similarly to the strength of the optical emission lines (in particular H{alpha}). Below P_1.4GHz_<10^24^W/Hz XUV is close to zero. XUV correlates strongly with the H{alpha} line strength, but only in sources with strong H{alpha} emission. We discuss whether the line emission might be due to photoionization by radiation from the parent galaxy, possibly with additional star formation, or if it requires the presence of a non-stellar active galactic nucleus component. XUV and the slope of the mid-IR are strongly correlated, as measured by the WISE bands in the interval 3.4 to 22{mu}m, in the sense that sources with a strong UV excess also have stronger IR emission. There is an inverse correlation between XUV and central black hole mass: the M_BH_ of objects with strong UV excess is on average two to three times less massive than that of objects without UV excess. Low-luminosity radio galaxies tend to be more massive and contain more massive black holes.
2429. Nearby Seyfert galaxies FIR emissions
ID:
ivo://CDS.VizieR/J/MNRAS/458/4512
Title:
Nearby Seyfert galaxies FIR emissions
Short Name:
J/MNRAS/458/4512
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present far-infrared (FIR) 70-500{mu}m imaging observations obtained with Herschel/Photodetector Array Camera (PACS) and Spectral and Photometric Imaging REceiver (SPIRE) of 33 nearby (median distance of 30Mpc) Seyfert galaxies from the Revised Shapley-Ames (RSA) catalogue. We obtain the FIR nuclear (r=1kpc and r=2kpc) and integrated spectral energy distributions (SEDs). We estimate the unresolved nuclear emission at 70{mu}m and we fit the nuclear and integrated FIR SEDs with a grey body model. We find that the integrated FIR emission of the RSA Seyferts in our sample is dominated by emission from the host galaxy, with dust properties similar to those of normal galaxies (non-AGN). We use four criteria to select galaxies whose nuclear 70{mu}m emission has a significant AGN contribution: (1) elevated 70/160{mu}m flux ratios, (2) spatially resolved, high dust temperature gradient, (3) 70{mu}m excess emission with respect to the fit of the FIR SEDs with a grey body, and (4) excess of nuclear SFR obtained from 70{mu}m over SFR from mid-infrared indicators. 16 galaxies (48 per cent of the initial sample) satisfy at least one of these conditions, whereas 10 satisfy half or more. After careful examination of these, we select six bona fide candidates (18 per cent of the initial sample) and estimate that ~40-70 per cent of their nuclear (r=1-2kpc) 70{mu}m emission is contributed by dust heated by the AGN.
2430. Near-infrared Mira period-luminosity relations in M33
ID:
ivo://CDS.VizieR/J/AJ/156/112
Title:
Near-infrared Mira period-luminosity relations in M33
Short Name:
J/AJ/156/112
Date:
21 Oct 2021
Publisher:
CDS
Description:
We analyze sparsely sampled near-infrared (JHK_s_) light curves of a sample of 1781 Mira variable candidates in M33, originally discovered using I-band time-series observations. We extend our single-band semi-parametric Gaussian process modeling of Mira light curves to a multiband version and obtain improved period determinations. We use our previous results on near-infrared properties of candidate Miras in the LMC to classify the majority of the M33 sample into oxygen- or carbon-rich subsets. We derive period-luminosity relations for O-rich Miras and determine a distance modulus for M33 of 24.80+/-0.06 mag.