- ID:
- ivo://CDS.VizieR/J/A+A/315/348
- Title:
- BVI photometry of two Orion galaxies
- Short Name:
- J/A+A/315/348
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Two relatively faint (B=15.7 and B=18.4mag, respectively), low velocity (+276 and +322km/s) galaxies were imaged with a CCD in the B, V, I bands at the prime focus of the 6m telescope on 16 October 1993. By means of the brightest stars we estimated their distances to be 6.4 and 5.5(+/-2)Mpc, assuming a galactic extinction of 2.7 and 2.9mag, respectively. We note that these isolated irregular dwarfs are located to a high Supergalactic latitude, -63deg, and their low radial velocities may be the result of a retarded expansion along the polar axis of the Local cloud of galaxies.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/121/870
- Title:
- BVI photometry of Variables in M33
- Short Name:
- J/AJ/121/870
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The DIRECT project aims to determine direct distances to two important galaxies in the cosmological distance ladder - M31 and M33 - using detached eclipsing binaries (DEBs) and Cepheids. We present the results of the first large-scale CCD-based search for variables in M33. We have observed two fields located in the central region of M33 for a total of 95 nights on the F. L. Whipple Observatory 1.2 m telescope and 36 nights on the Michigan-Dartmouth-MIT 1.3 m telescope. We have found a total of 544 variables, including 251 Cepheids and 47 eclipsing binaries. The catalog of variables is available on-line, along with finding charts and BVI light curve data (consisting of 8.2x10^4^ individual measurements). The complete set of CCD frames is available upon request.
- ID:
- ivo://CDS.VizieR/J/AJ/110/2400
- Title:
- BVI photometry of V728 Her
- Short Name:
- J/AJ/110/2400
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The W UMa system V728 Her has been observed photometrically in B, V, and I_c passbands at the RAO over five seasons and spectroscopically at DAO over three seasons to obtain radial velocities. New times of minima are provided and a period analysis confirms previous ephemerides. The light and radial velocity curves were analyzed with the latest University of Calgary enhancements to the Wilson-Devinney program and new solutions found. The best model is that involving a contact system with convective atmospheres. In probing the best solution possible, use was made of the enhanced reflection and second-order limb-darkening calculations available in the 1993 version of the WD program. The mass ratio is found to be 0.1786+/-0.0023. The contact parameter is found to be f=0.71+/-0.11. The masses are determined to be 1.654+/-0.037M_{sun}_ and 0.295+/-0.009M_{sun}_ and the radii are 1.784+/-0.015R_{sun}_ and 0.867+/-0.054R_{sun}_, respectively. The determined temperature difference, T2-T1 is 165+/-19K, and the luminosities for components 1 and 2 are 5.5+/-0.5L_{sun}_ and 1.4+/-0.3L_{sun}_, respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/466/181
- Title:
- BVI photometry of Whiting 1
- Short Name:
- J/A+A/466/181
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recently Carraro (2005ApJ...621L..61C) drew attention to the remarkable star cluster Whiting 1, showing that it lies at about 40kpc from the Sun and is therefore unquestionably a member of the Galactic halo (l=-60.6{deg}). Its Color Magnitude Diagram (CMD) indicated that Whiting 1 is very young (~5Gyrs) for a globular cluster. It is highly likely that Whiting 1 is originated in a dwarf galaxy that has since been disrupted by the Milky Way. The main purpose of the present study is to better constrain the properties of Whiting 1, and assess whether it belongs to a stellar stream from the Sagittarius Dwarf Spheroidal Galaxy (Sgr dSph). Deep CCD photometry in the BVI pass-band obtained with the VLT is used to improve the quality of the CMD, and provide more solid estimates of the cluster distance and age, while high resolution spectra of three evolved stars obtained at Magellan is used to derive the cluster kinematics and analyze its possible membership to the Sgr dSph. We demonstrate that - independently on the Halo model employed - Whiting 1 is part of the trailing stream of the Sgr dSph. We derive a new age estimate of 6.5^+1.0^_-0.5_Gyr, and a smaller heliocentric distance of 29.4^+1.8^_-2.0_kpc. The number of globular clusters confirmed to be members of Sgr dSph is now 6. Among these clusters, Whiting 1 is particularly interesting, being the youngest and one of the most metal rich. The existence of Whiting 1 shows how the Sgr dSph was able to form star clusters for a period at least of 6Gyr.
- ID:
- ivo://CDS.VizieR/J/A+A/360/529
- Title:
- BVI photometry of 4 young open clusters
- Short Name:
- J/A+A/360/529
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD observations in the B, V, and I passbands obtained for stars in the fields of the open clusters Pismis 22, NGC 6178, NGC 6216, and Ruprecht 130, projected not far from the Galactic centre (|l|<30{deg}, |b|<2{deg}). The sample consists of about 790 stars reaching down to V~18-19mag. From the analysis of the colour magnitude diagrams, we confirmed the physical reality of the clusters and derived their reddening, distance and age. In addition, we obtained flux-calibrated integrated spectra in the range 3500-9200{AA} for the cluster sample. The equivalent widths of the Balmer lines provided us with age estimates, while the comparison with template spectra allowed us to derive both foreground reddening and age. The photometric and spectroscopic results reveal that the four studied objects are young open clusters with ages ranging between 35 and 50Myr. The clusters, located between 1.0kpc and 4.3kpc from the Sun, are affected by different amounts of interstellar visual absorption (0.6=~A_v_=~6.0).
- ID:
- ivo://CDS.VizieR/J/MNRAS/375/1220
- Title:
- BVI photometry of young stars in 10 clusters
- Short Name:
- J/MNRAS/375/1220
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have selected pre-main-sequence (PMS) stars in 12 groups of notional ages ranging from 1 to 35Myr, using heterogeneous membership criteria. Using these members we have constructed empirical isochrones in V, V-I colour-magnitude diagrams. This allows us to identify clearly the gap between the radiative main sequence and the convective PMS (the RC gap). We follow the evolution of this gap with age and show that it can be a useful age indicator for groups less than =15 Myr old. We also observe a reduction in absolute spreads about the sequences with age. Finally, the empirical isochrones allow us to place the groups in order of age, independently of theory. The youngest groups can be collated into three sets of similar ages. The youngest set is the ONC, NGC 6530 and IC 5146 (nominally 1Myr); next Cep OB3b, NGC 2362, Ori and NGC 2264 (nominally 3Myr); and finally Ori and IC 348 (nominally 45Myr). This suggests Cep OB3b is younger than previously thought, and IC 348 older. For IC 348 the stellar rotation rate distribution and fraction of stars with discs imply a younger age than we derive. We suggest this is because of the absence of O-stars in this cluster, whose winds and/or ionizing radiation may be an important factor in the removal of discs in other clusters.
2227. BVI TX Cnc light curves
- ID:
- ivo://CDS.VizieR/J/AJ/138/680
- Title:
- BVI TX Cnc light curves
- Short Name:
- J/AJ/138/680
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present B-, V-, and I-band CCD photometry of the W UMa-type binary system TX Cnc, which is a member star of the Praesepe open cluster. Based on the observations, new ephemeris and a revised photometric solution of the binary system were derived.
- ID:
- ivo://CDS.VizieR/J/ApJ/660/81
- Title:
- BViz photometry of TKRS blue galaxies in GOODS-N
- Short Name:
- J/ApJ/660/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We examine the radius-luminosity (R-L) relation for blue galaxies in the Team Keck Redshift Survey (TKRS) of GOODS-N. We compare with a volume-limited, Sloan Digital Sky Survey sample and find that the R-L relation has evolved to lower surface brightness since z=1. Based on the detection limits of GOODS, this cannot be explained by incompleteness in low surface brightness galaxies. Number density arguments rule out a pure radius evolution. It can be explained by a radius-dependent decline in B-band luminosity with time.
- ID:
- ivo://CDS.VizieR/J/A+A/567/A1
- Title:
- BVJH photometry of Andrews-Lindsay 1 field
- Short Name:
- J/A+A/567/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Andrews-Lindsay 1 is a pertinent open cluster because it may host the planetary nebula (PN) PHR 1315-6555, yet ambiguities linger concerning its fundamental parameters (>50% scatter). New multiband BVJHW_1-4_ photometry for cluster and field stars, in concert with observations of recently discovered classical Cepheids, were used to constrain the reddening and velocity-distance profiles along the sightline. That analysis yielded the following parameters for the cluster: E(J-H)=0.24+/-0.03, d=10.0+/-0.4kpc (d_JH_=9.9+/-0.6kpc, d_BV_=10.1+/-0.5kpc), and log{tau}=8.90+/-0.15. The steep velocity-distance gradient along l~305{deg} indicates that two remote objects sharing spatial and kinematic parameters (i.e., PHR 1315-6555 and Andrews-Lindsay 1) are associated, thus confirming claims that the PN is a cluster member. The new distance for PHR 1315-6555 is among the most precise established yet for a Galactic PN ({sigma}/d=4%).
- ID:
- ivo://CDS.VizieR/J/A+A/629/A58
- Title:
- B2 0258+35 VLA and VLBI HI absorption spectra
- Short Name:
- J/A+A/629/A58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Low-luminosity radio-loud active galactic nuclei (AGN) are of importance in studies concerning feedback from radio AGN since a dominant fraction of AGN belong to this class. We report high-resolution Very Large Array (VLA) and European VLBI Network (EVN) observations of HI 21cm absorption from a young, compact steep-spectrum radio source, B2 0258+35, nested in the early-type galaxy NGC 1167, which contains a 160kpc HI disc. Our VLA and EVN HI absorption observations, modelling, and comparison with molecular gas data suggest that the cold gas in the centre of NGC 1167 is very turbulent (with a velocity dispersion of ~90km/s) and that this turbulence is induced by the interaction of the jets with the interstellar medium (ISM). Furthermore, the ionised gas in the galaxy shows evidence of shock heating at a few kpc from the radio source. These findings support the results from numerical simulations of radio jets expanding into a clumpy gas disc, which predict that the radio jets in this case percolate through the gas disc and drive shocks into the ISM at distances much larger than their physical extent. These results expand the number of low-luminosity radio sources found to impact the surrounding medium, thereby highlighting the possible relevance of these AGN for feedback.