- ID:
- ivo://CDS.VizieR/J/A+AS/142/73
- Title:
- Galaxies morphology and IR photometry IV.
- Short Name:
- J/A+AS/142/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared (H band) surface photometry of 170 galaxies, obtained in 1997 using the Calar Alto 2.2 m telescope equipped with the NICMOS3 camera MAGIC. The majority of our targets are selected among bright members of the Virgo cluster, however galaxies in the A262 and Cancer clusters and in the Coma/A1367 supercluster are also included. This data set is aimed at complementing the NIR survey in the Virgo cluster discussed in Boselli et al. (1997A&A...324L..13B) and in the Coma Supercluster, presented in Papers I, II and III of this series. Magnitudes at the optical radius, total magnitudes, isophotal radii and light concentration indices are derived.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/361/863
- Title:
- Galaxies morphology and IR photometry. V.
- Short Name:
- J/A+A/361/863
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared H-band (1.65{mu}m) surface brightness profile decomposition for 1157 galaxies in five nearby clusters of galaxies: Coma, A1367, Virgo, A262 and Cancer, and in the bridge between Coma and A1367 in the "Great Wall". The optically selected (m_pg_<=16.0) sample is representative of all Hubble types, from E to Irr+BCD, except dE and of significantly different environments, spanning from isolated regions to rich clusters of galaxies. We model the surface brightness profiles with a de Vaucouleurs r^1/4^ law (dV), with an exponential disk law (E), or with a combination of the two (B+D). From the fitted quantities we derive the H band effective surface brightness ({mu}_e_) and radius (r_e_) of each component, the asymptotic magnitude H_T_ and the light concentration index C_31_. We find that: i) Less than 50% of the Elliptical galaxies have pure dV profiles. The majority of E to Sb galaxies is best represented by a B+D profile. All Scd to BCD galaxies have pure exponential profiles. ii) The type of decomposition is a strong function of the total H band luminosity (mass), independent of the Hubble classification: the fraction of pure exponential decompositions decreases with increasing luminosity, that of B+D increases with luminosity. Pure dV profiles are absent in the low luminosity range L_H_<10^10^L_{sun}_ and become dominant above 10^11^L_{sun}_.
- ID:
- ivo://CDS.VizieR/J/MNRAS/332/422
- Title:
- Galaxies morphology and IR photometry. VIII
- Short Name:
- J/MNRAS/332/422
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the distribution of a statistical sample of nearby galaxies in the {kappa}-space ({kappa1}{prop.to}logM, {kappa}2{prop.to}log(Ie)^3^*M/L, {kappa}3{prop.to}M/L). Our study is based on near-IR (H-band: {lamdba}=1.65{mu}m) observations, for the first time comprising early- and late-type systems. Our data confirm that the mean effective dynamical mass-to-light ratio M/L of the E+S0+S0a galaxies increases with increasing effective dynamical mass M, as expected from the existence of the Fundamental Plane relation. Conversely, spiral and Im/BCD galaxies show broad distribution in M/L with no detected trend of M/L with M, the former galaxies having M/L values about twice larger than the latter, on average. For all the late-type galaxies, the M/L increases with decreasing effective surface intensity Ie, consistent with the existence of the Tully-Fisher relation.
- ID:
- ivo://CDS.VizieR/J/ApJ/744/44
- Title:
- H{alpha} and UV fluxes in nearby galaxies
- Short Name:
- J/ApJ/744/44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We consider the effects of non-constant star formation histories (SFHs) on H{alpha} and GALEX far-ultraviolet (FUV) star formation rate (SFR) indicators. Under the assumption of a fully populated Chabrier initial mass function (IMF), we compare the distribution of H{alpha}-to-FUV flux ratios from ~1500 simple, periodic model SFHs with observations of 185 galaxies from the Spitzer Local Volume Legacy survey. We find a set of SFH models that are well matched to the data, such that more massive galaxies are best characterized by nearly constant SFHs, while low-mass systems experience burst amplitudes of ~30 (i.e., an increase in the SFR by a factor of 30 over the SFR during the inter-burst period), burst durations of tens of Myr, and periods of ~250 Myr; these SFHs are broadly consistent with the increased stochastic star formation expected in systems with lower SFRs. We analyze the predicted temporal evolution of galaxy stellar mass, R-band surface brightness, H{alpha}-derived SFR, and blue luminosity, and find that they provide a reasonable match to observed flux distributions. We find that our model SFHs are generally able to reproduce both the observed systematic decline and increased scatter in H{alpha}-to-FUV ratios toward low-mass systems, without invoking other physical mechanisms.
- ID:
- ivo://CDS.VizieR/J/A+A/396/449
- Title:
- H{alpha} surface photometry in Virgo
- Short Name:
- J/A+A/396/449
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- H{alpha}+[NII] imaging observations of 369 late-type (spiral) galaxies in the Virgo cluster and in the Coma/A1367 supercluster are analyzed, covering 3 rich nearby clusters (A1367, Coma and Virgo) and nearly isolated galaxies in the Great-Wall. They constitute an optically selected sample (mp<16.0) observed with ~60% completeness. These observations provide us with the current (T<10^7^yrs) star formation properties of galaxies that we study as a function of the clustercentric projected distances (Theta). The expected decrease of the star formation rate (SFR), as traced by the H{alpha} equivalent width, with decreasing Theta is found only when galaxies brighter than Mp~19.5 are considered. Fainter objects show no or reverse trends. We also include in our analysis Near Infrared data, providing information on the old (T>10^9^yrs) stars. Put together, the young and the old stellar indicators give the ratio of currently formed stars over the stars formed in the past, or "birthrate" parameter b. For the considered galaxies we also determine the "global gas content" combining HI with CO observations. We define the "gas deficiency'' parameter as the logarithmic difference between the gas content of isolated galaxies of a given Hubble type and the measured gas content.
- ID:
- ivo://CDS.VizieR/J/A+A/428/837
- Title:
- HII regions in minor mergers of galaxies
- Short Name:
- J/A+A/428/837
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the B, V and I photometry of eleven southern minor mergers. The total apparent B magnitude, integrated B-V and V-I colours were measured. We built B, V, and I equivalent profiles for each galaxy and decomposed them into bulge and disk components when possible. From H{alpha}+N[II] images we have estimated the basic photometric parameters of the HII regions, such as position, size, B-V and V-I colours, H{alpha}+[NII] luminosity and EW(H{alpha}+[NII]) equivalent width.
- ID:
- ivo://CDS.VizieR/J/AJ/138/1667
- Title:
- HST survey of young clusters in M31. III.
- Short Name:
- J/AJ/138/1667
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Surface brightness profiles for 23 M31 star clusters were measured using images from the Wide Field Planetary Camera 2 on the Hubble Space Telescope, and fitted to two types of models to determine the clusters' structural properties. The clusters are primarily young (~108yr) and massive (~104.5M_{sun}_), with median half-light radius 7pc and dissolution times of a few Gyr. The properties of the M31 clusters are comparable to those of clusters of similar age in the Magellanic Clouds. Simulated star clusters are used to derive a conversion from statistical measures of cluster size to half-light radius so that the extragalactic clusters can be compared to young massive clusters in the Milky Way. All three sets of star clusters fall approximately on the same age-size relation. The young M31 clusters are expected to dissolve within a few Gyr and will not survive to become old, globular clusters. However, they do appear to follow the same fundamental plane (FP) relations as old clusters; if confirmed with velocity dispersion measurements, this would be a strong indication that the star cluster FP reflects universal cluster formation conditions.
- ID:
- ivo://CDS.VizieR/J/A+AS/129/583
- Title:
- Hubble Deep Field surface photometry
- Short Name:
- J/A+AS/129/583
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The detailed surface photometry of a sample of early-type galaxies in the Hubble Deep Field is presented as part of a long-term project aimed to settle strong observational constraints to the theories modelling the evolution of elliptical galaxies from the early stages. The sample has been extracted, in the V_606_ band, from the database provided by the ESO-STECF-HDF Group (Couch, 1996, <http://ecf.hq.eso.org>). The selection criteria involve the total magnitude, the number of pixels detected above the background level and an automatic star/galaxy classifier. Moreover, form visual inspection of the frames, we excluded the galaxies showing unambiguous late-type morphology. The analysis of the luminosity and geometrical profiles, carried out on the 162 candidates obeying our selection criteria, resulted in a list of 99 'bona fide' early-type galaxies, for which accurate total magnitudes and effective radii were computed on the basis of the equivalent luminosity profiles. The comparison with the magnitudes given by Williams et al. (1996, Cat. <J/AJ/112/1335>) indicates that the automated photometry tends to underestimate the total luminosity of the ellipticals. The luminosity profiles of most of galaxies in our sample follow fairly well the de~Vaucouleurs law ('Normal' profiles). However, a relevant fraction of galaxies, even following the r^1/4^ law in the main body light distribution, exhibit in the inner region a flattening of the luminosity profile not attributable to the PSF (`Flat' profiles) or, in some cases, a complex (multi-nucleus) structure (`Merger' profiles). A statistically significant correlation is found between the shapes of the luminosity profiles and the ellipticity distribution. In particular, the average ellipticity of galaxies belonging to the `Flat' and `Merger' classes is significantly higher than that of the `Normal' galaxies. Finally, even taken into account the relevant uncertainty of the outer position angle profiles, the amount of isophotal twisting of HDF ellipticals turns out to be significantly larger with respect to that of the local samples.
- ID:
- ivo://CDS.VizieR/J/A+A/649/A138
- Title:
- Intensity profiles for GC1 of M81
- Short Name:
- J/A+A/649/A138
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Researching the properties of the brightest globular cluster (referred to as GC1) in M 81 can provide a fossil record of the earliest stages of galaxy formation and evolution. The Beijing-Arizona-Taiwan-Connecticut (BATC) Multicolour Sky Survey has carried out deep exposures of M 81. We derive the magnitudes in intermediate-band filters of the BATC system for GC1 and determine its age, mass, and structural parameters. GC1 was observed by BATC using 14 intermediate-band filters covering a wavelength range of 4000-10000{AA}. Based on photometric data in BATC and Two Micron All Sky Survey near-infrared JHKs filters, we constructed an extensive spectral energy distribution of GC1, spanning the wavelength range from 4000 to 20000{AA}. By comparing multicolour photometry with theoretical single stellar population synthesis models, we derived the age and mass of GC1. In addition, we obtained ellipticities, position angles, and surface brightness profiles for GC1 based on the images of deep observations with the Advanced Camera for Surveys on the Hubble Space Telescope. GC1 is better fitted by the Wilson model than by the King and Sersic models in the F606W filter, and it is better fitted by the Sersic model than by the King and Wilson models in the F814W filter. The 'best-fit' half-light radius of GC1 obtained here is 5.59pc, which is larger than the majority of normal globular clusters (GCs) of the same luminosity. The age and mass of GC1 estimated here are 13.0+/-2.90Gyr and 1.06-1.48x10^7^M_{sun}_, respectively. The Rh versus MV diagram shows that GC1 occupies the same area as extended star clusters. Therefore, we suggest that GC1 is more likely an accreted former nuclear star cluster than a classical GC similar to most of those in the Milky Way.
- ID:
- ivo://CDS.VizieR/J/AJ/127/704
- Title:
- Low surface brightness galaxies in SDSS
- Short Name:
- J/AJ/127/704
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present results of a pilot study to use imaging data from the Sloan Digital Sky Survey (SDSS) to search for low surface brightness (LSB) galaxies. For our pilot study we use a test sample of 92 galaxies from the Impey et al. catalog distributed over 93 SDSS fields of the Early Data Release (EDR, <J/AJ/123/567>). Many galaxies from the test sample are either LSB or dwarf galaxies. To deal with the SDSS data most effectively, a new photometry software was created, which is described in this paper. We present the results of the selection algorithms applied to these 93 EDR fields. Two galaxies from the Impey et al. (1996, <J/ApJS/105/209>) test sample are very likely artifacts, as confirmed by follow-up imaging. With our algorithms we were able to recover 87 of the 90 remaining test sample galaxies, implying a detection rate of ~96.5%. The three missed galaxies fall too close to very bright stars or galaxies. In addition, 42 new galaxies with parameters similar to the test sample objects were found in these EDR fields (i.e.,~47% additional galaxies). We present the main photometric parameters of all identified galaxies and carry out first statistical comparisons. We tested the quality of our photometry by comparing the magnitudes for our test sample galaxies and other bright galaxies with values from the literature. All these tests yielded consistent results. We briefly discuss a few unusual galaxies found in our pilot study, including an LSB galaxy with a two-component disk and 10 new giant LSB galaxies.
