- ID:
- ivo://CDS.VizieR/J/AJ/122/1125
- Title:
- BVRI photometry in 3 high-z clusters
- Short Name:
- J/AJ/122/1125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New photometric and spectroscopic observations of galaxies in the directions of three distant clusters are presented as part of our ongoing high-redshift cluster survey. The clusters are Cl 1324+3011 at z=0.76, Cl 1604+4304 at z=0.90, and Cl 1604+4321 at z=0.92. We have spectroscopically confirmed cluster membership for 2040 galaxies in each system and have also obtained spectra for over 280 field galaxies spanning the range 0<z<2.5.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/419/167
- Title:
- BVRI photometry in metal-poor binaries
- Short Name:
- J/A+A/419/167
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explored the regions within a radius of 25 arcsec around 473 nearby, low-metallicity G- to M-type stars using (VR)I optical filters and small-aperture telescopes. About 10% of the sample was searched up to angular separations of 90 arcsec. We applied photometric and astrometric techniques to detect true physical companions to the targets. The great majority of the sample stars was drawn from the Carney-Latham surveys; their metallicities range from roughly solar to [Fe/H]=-3.5dex. Our I-band photometric survey detected objects that are between 0 and 5mag fainter (completeness) than the target stars; the maximum dynamical range of our exploration is 9mag.
- ID:
- ivo://CDS.VizieR/J/AJ/145/165
- Title:
- BVRI photometry in NGC 6496
- Short Name:
- J/AJ/145/165
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-quality BVRI photometric data in the field of globular cluster NGC6496 obtained with the SOAR Telescope Adaptive Module (SAM). Our observations were collected as part of the ongoing SAM commissioning. The distance modulus and cluster color excess as found from the red clump are (m-M)_V_=15.71+/-0.02mag and E(V-I)=0.28+/-0.02mag. An age of 10.5+/-0.5Gyr is determined from the difference in magnitude between the red clump and the subgiant branch. These parameters are in excellent agreement with the values derived from isochrone fitting. From the color-magnitude diagram we find a metallicity of [Fe/H]=-0.65dex and hence support a disk classification for NGC 6496. The complete BVRI data set for NGC6469 is made available in the electronic edition of the Journal.
- ID:
- ivo://CDS.VizieR/J/PASP/117/1325
- Title:
- BVRI photometry in NGC4147
- Short Name:
- J/PASP/117/1325
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New BVRI broadband photometry and astrometry are presented for the globular cluster NGC 4147, based upon measurements derived from 524 ground-based CCD images mostly either donated by colleagues or retrieved from public archives. We have also reanalyzed five exposures of the cluster obtained with WFPC2 on the Hubble Space Telescope in the F439W and F555W (B and V) filters.
- ID:
- ivo://CDS.VizieR/J/PASP/117/37
- Title:
- BVRI photometry in NGC 2419, Pal 4, and Pal 14
- Short Name:
- J/PASP/117/37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results from work done to extend the Johnson-Cousins BVRI photometric standard sequence to faint levels of V~21mag in compact fields is presented. Such calibration and extension of sequences is necessary to fill a calibration gap if reliable photometry from modest aperture telescopes in space (e.g., the Hubble Space Telescope) or terrestrial telescopes with apertures exceeding 4m is to be done. Sequences like the ones presented here, which cover a large range in brightness as well as color, will allow photometric calibration to be done efficiently and will also make such work less prone to systematic sources of error. Photometry of stars in approximately 10'x10' fields around three globular clusters (NGC 2419, Pal 4, and Pal 14) are presented from data acquired over several photometric nights. In each field, several stars are measured in B, V, R, and I passbands, with standard errors in the mean less than 0.015mag from random errors, to levels fainter than V=21mag.
- 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/128/315
- Title:
- BVRI photometry of blazars
- Short Name:
- J/A+AS/128/315
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of both BVRI CCD photometric monitoring and fast photometry for 8 blazars and variable quasars are presented. There is intraday variability for 6 blazars and very short timescales (minutes to two hours) variability for 5 objects. Implications for relativistic beaming are briefly discussed.
- ID:
- ivo://CDS.VizieR/J/A+AS/136/455
- Title:
- BVRI photometry of 3 BL Lac objects
- Short Name:
- J/A+AS/136/455
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of optical photometric (BVRI) monitoring of three BL Lac objects over a time interval of about four years are presented. The sources are three classical radio-selected BL Lac objects, BL Lac, OJ 287 and PKS 0735+178. During our observation OJ 287 was in the stage of a large periodic outburst which consisted of at least two peaks. Almost all the observations obtained over consecutive nights detected intranight variations. In 1995 and 1996 BL Lac kept in faint states, with fewer and smaller rapid flares and fluctuations. On the contrary, in late 1997 BL Lac was at the stage of a large outburst, accompanied with much more large amplitude rapid flares and fluctuations. PKS 0735+178 was almost at its faint end from 1994 to early 1998. Over this time interval, the intraday variations and microvariations in PKS 0735+178 were rare and the amplitude was very small, except a rapid darkening of ~0.4mag on 24 January 1995. Previous work by Webb et al. (1988AJ.....95..374W), Wagner et al. (1996AJ....111.2187W) and Pian et al. (1997ApJ...486..784P) also showed the same behaviour of variability as BL Lac and PKS 0735+178 in BL Lac, S5 0716+714, PKS 2155-304, respectively. We propose that the motion of orientation of the relativistic jet in a BL Lac object be responsible for these variability behaviours.
- ID:
- ivo://CDS.VizieR/J/A+AS/132/83
- Title:
- BVRI photometry of 7 BL Lac objects
- Short Name:
- J/A+AS/132/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Seven BL Lac objects have been photometrically observed in an effort to study the difference of optical intraday variability between the radio-selected BL Lac objects (RBLs) and X-ray-selected BL Lac objects (XBLs). The objects we observed are selected arbitrarily. They are four RBLs, PKS 0735+178, PKS 0754+101, OJ 287 and BL Lac, and three XBLs, H 0323+022, H 0548-322 and H 2154-304. During the observation all of them exhibited microvariation, and H 0323+022 and H 0548-322 sometimes showed brightness oscillation. PKS 0735+178 and BL Lac were in their faint states and not very active. It seems that RBLs do not show microvariability more frequently than XBLs.
- ID:
- ivo://CDS.VizieR/J/AJ/134/778
- Title:
- BVRI photometry of candidate subdwarfs
- Short Name:
- J/AJ/134/778
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Optical (BVRI) photometric measurements of a sample of 564 candidate cool subdwarfs in the nearby halo are presented. The stars generally span the color range 0.4<(B-V)<1.8; hence, the sample is composed of early F- through early M-type stars on the subdwarf sequence. The sample is selected from the revised NLTT catalog of Gould and Salim and Salim and Gould via a reduced proper motion diagram. The photometry is precise and accurate; in particular, for stars with 9<V<13.5 the photometry is accurate to 0.013, 0.015, 0.012, and 0.013mag in V, B-V, V-R, and V-I, respectively. For stars with 13.5<V<16 the photometry is accurate to 0.022, 0.018, 0.013, and 0.018mag in the same bands.
