- ID:
- ivo://CDS.VizieR/J/ApJ/710/1664
- Title:
- BV photometry in Leo IV and Leo V dSphs
- Short Name:
- J/ApJ/710/1664
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained deep photometry in two 1{deg}x1{deg} fields covering the close pair of dwarf spheroidal galaxies Leo IV and Leo V and part of the area in between. From the distribution of likely red giant branch (RGB) and horizontal-branch (HB) stars in the data set, we find that both Leo IV and Leo V are significantly larger than indicated by previous measurements based on shallower data. With a half-light radius of r_h_=4.6'+/-0.8' (206+/-36pc) and r_h_=2.6'+/-0.6' (133+/-31pc), respectively, both systems are now well within the physical size bracket of typical dwarf spheroidal Milky Way satellites. Both are also found to be significantly elongated with an ellipticity of {epsilon}~0.5, a characteristic shared by many of the fainter (M_V_>-8) Milky Way dwarf spheroidals. The large spatial extent of our survey allows us to search for extra-tidal features in the area between the two dwarf galaxies with unprecedented sensitivity. The spatial distribution of candidate RGB and HB stars in this region is found to be non-uniform at the ~3{sigma} level. We investigate different scenarios to explain the close proximity of Leo IV and Leo V, and the possible tidal bridge between them.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/146/141
- Title:
- BV photometry of dwarf Cepheids in Carina
- Short Name:
- J/AJ/146/141
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detection of 388 pulsating variable stars (and some additional miscellaneous variables) in the Carina dwarf spheroidal galaxy over an area covering the full visible extent of the galaxy and extending a few times beyond its photometric (King) tidal radius along the direction of its major axis. Included in this total are 340 newly discovered dwarf Cepheids (DCs), which are mostly located ~2.5mag below the horizontal branch and have very short periods (<0.1days), typical of their class and consistent with their location on the upper part of the extended main sequence of the younger populations of the galaxy. Several extra-tidal DCs were found in our survey up to a distance of ~1{deg} from the center of Carina. Our sample also includes RR Lyrae stars and anomalous Cepheids, some of which were found outside the galaxy's tidal radius as well. This supports past works that suggest that Carina is undergoing tidal disruption. We use the period-luminosity relationship for DCs to estimate a distance modulus of {mu}_0_=20.17+/-0.10mag, in very good agreement with the estimate from RR Lyrae stars. We find some important differences in the properties of the DCs of Carina and those in Fornax and the LMC, the only extragalactic samples of DCs currently known. These differences may reflect a metallicity spread, depth along the line of sight, and/or different evolutionary paths of the DC stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/385/361
- Title:
- BVRcIc photometry of NGC 821 globular clusters
- Short Name:
- J/MNRAS/385/361
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We performed a photometric study of globular clusters around the isolated elliptical galaxy NGC 821. B, V and R-band photometry come from the Mini-Mosaic imager on the 3.5-m Wisconsin Indiana Yale NOAO (WIYN) telescope. Observations were conducted between November 30 - December 2, 2005. Average seeing conditions were ~0.7". Two Hubble Space Telescope (HST) Wide-Field Planetary Camera 2 (WFPC2) fields were analysed in the V and I-bands. Objects in this catalogue are the globular cluster candidates according to the selection criteria detailed in the journal article. Astrometric solution is from USNO-B stars. Note the center of NGC 821 on this system is located at 02:08:21.118 +10:59:42.21. Photometry has been corrected for Galactic extinction and we used a distance modulus of m-M=31.75 in our analysis.
- ID:
- ivo://CDS.VizieR/J/A+A/445/901
- Title:
- BV(RI)c bands of Cepheids in IC 1613
- Short Name:
- J/A+A/445/901
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A set of six BV(RI)c observations collected with the WFI at the ESO 2.2m telescope have been used to derive multicolor data of Cepheids in IC 1613 identified in previous surveys. Since part of the previously known data were obtained only in V,I filters or without filter (Wh) bands, the method of Freedman has been applied to get reliable mean intensity values of Cepheid magnitudes in the various bands. The resulting slopes of the relations in the BVI bands are similar, within the uncertainties, to those previously obtained by other authors for the LMC. The distribution of the Cepheids in the period-color diagrams is compatible with a change near P about 10d as observed in LMC. The distribution in the color-color diagrams is more similar to that in SMC, and this should be related to the very low metallicity of the galaxy.
- ID:
- ivo://CDS.VizieR/J/A+AS/141/103
- Title:
- BVRI imaging of M 51-type pairs
- Short Name:
- J/A+AS/141/103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present decompositions of azimuthally averaged surface brightness profiles in optical B, V, R and I-bands for a sample of 40 M 51-type interacting galaxies. The profiles were modelled by an exponential disk and a spherical bulge described either by the R^1/4^ law or by an exponential function. Half of the galaxies were well fitted by both bulge models, whereas for 35% the exponential function was a better choice. Special care was taken on eliminating superpositions of the companion galaxies. The mean B-band central surface brightness {mu}_0_was found to be 21.5mag/arcsec^2^, which is near to the value originally found by Freeman (1970ApJ...160..811F), but the scatter was fairly large. Galaxy interactions have strongly modified the disks in many of the galaxies in the sample. For example, six of them had extremely flat brightness profiles outside the exponential part of the disk, and many showed significant isophotal twists.
- ID:
- ivo://CDS.VizieR/J/ApJ/743/118
- Title:
- BVRIJHK photometry of the 2008 OT in NGC 300
- Short Name:
- J/ApJ/743/118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 2008 optical transient in NGC 300 is one of a growing class of intermediate-luminosity transients that brighten several orders of magnitude from a previously optically obscured state. The origin of their eruptions is not understood. Our multi-wavelength photometry and spectroscopy from maximum light to more than a year later provide a record of its post-eruption behavior. We describe its changing spectral energy distribution, the evolution of its absorption- and emission-line spectrum, the development of a bipolar outflow, and the rapid transition from a dense wind to an optically thin ionized wind. In addition to strong, narrow hydrogen lines, the F-type absorption-line spectrum of the transient is characterized by strong CAII and [CAII] emission. The very broad wings of the CAII triplet and the asymmetric [CAII] emission lines are due to strong Thomson scattering in the expanding ejecta. Post-maximum, the hydrogen and CaII lines developed double-peaked emission profiles that we attribute to a bipolar outflow. Between approximately 60 and 100 days after maximum, the F-type absorption spectrum, formed in its dense wind, weakened and the wind became transparent to ionizing radiation. We discuss the probable evolutionary state of the transient and similar objects such as SN 2008S and conclude that they were most likely post-red supergiants or post-asymptotic giant branch stars on a blue loop to warmer temperatures when the eruption occurred. These objects are not luminous blue variables.
- ID:
- ivo://CDS.VizieR/J/AJ/122/38
- Title:
- BVRI photometry of Abell 2443
- Short Name:
- J/AJ/122/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present broadband photometry and provide a quantitative analysis of the structure of galaxies in the inner region of the Abell Cluster 2443 (z~0.1). The galaxy parameters have been derived by fitting a two-component model (Sersic r^1/n^ bulge and exponential disk) to a magnitude-limited sample. Using a new method of analysis that takes into account the effects of seeing on the structural parameters and considers ellipticity as an active parameter, we avoid systematic errors arising from assumptions of circular symmetry. Of the sample galaxies, 76% were classified with these models, while the rest were morphologically peculiar. For the spiral galaxies, the relation between n and B/D is consistent with the trend observed in nearby field galaxy samples. The Sersic index n (which can be considered as a concentration index) of the elliptical galaxies is correlated with the local surface density of the cluster. Monte Carlo simulations were used to check the reliability of the method and determine the magnitude selection criteria. Observations were obtained on 1998 August 19 at the 2.5 m Nordic Optical Telescope (NOT) at the Observatorio del Roque de los Muchachos on La Palma. The prime-focus CCD camera was used with pixel scale of 0.11"/pix, and the seeing ranged from FWHM 0.88" to 1".
- ID:
- ivo://CDS.VizieR/J/A+AS/142/425
- Title:
- BVRI photometry of 6 galaxies
- Short Name:
- J/A+AS/142/425
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometry of the brightest stars in six nearby spiral and irregular galaxies with corrected radial velocities from 340 to 460km/s. Three of them are resolved into stars for the first time. Based on luminosity of the brightest blue stars we estimate the following distances to the galaxies: 5.0Mpc for NGC 784, 9.2Mpc for NGC 2683, 8.9Mpc for NGC 2903, 4.1Mpc for NGC 5204, 6.8Mpc for NGC 5474, and 8.7Mpc for NGC 5585.
- ID:
- ivo://CDS.VizieR/J/AJ/134/2286
- Title:
- BVRI photometry of isolated spirals
- Short Name:
- J/AJ/134/2286
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A release of multicolor broadband (BVRI) photometry for a subsample of 44 isolated spirals drawn from the Catalogue of Isolated Galaxies is presented. Total magnitudes and colors at various circular apertures, as well as some global structural/morphological parameters, are estimated. Morphology is reevaluated through optical and sharp-filtered R-band images, (B-I) color index maps, and archived near-IR JHK images from the Two Micron All Sky Survey. The CAS structural parameters (concentration, asymmetry, and clumpiness) were calculated from the images in each of the bands.
- ID:
- ivo://CDS.VizieR/J/AJ/154/81
- Title:
- BVRI photometry of luminous stars in M31 and M33
- Short Name:
- J/AJ/154/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first four years of BVRI photometry from an on-going survey to annually monitor the photometric behavior of evolved luminous stars in M31 and M33. Photometry was measured for 199 stars at multiple epochs, including 9 classic Luminous Blue Variables (LBVs), 22 LBV candidates, 10 post-RGB A/F type hypergiants, and 18 B[e] supergiants. At all epochs, the brightness is measured in the V-band and at least one other band to a precision of 0.04-0.10 mag down to a limiting magnitude of 19.0-19.5. Thirty three stars in our survey exhibit significant variability, including at least two classic LBVs caught in S Doradus-type outbursts. A hyperlinked version of the photometry catalog is at http://go.uis.edu/m31m33photcat