- ID:
- ivo://CDS.VizieR/J/AJ/123/2206
- Title:
- BRI photometry of 3 QSO fields
- Short Name:
- J/AJ/123/2206
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper describes the acquisition and analysis of imaging data for the identification of galaxies associated with z~4 damped Ly{alpha} systems. We present deep BRI images of three fields known to contain four z~4 damped systems. We discuss the reduction and calibration of the data, detail the color criteria used to identify z~4 galaxies, and present a photometric redshift analysis to complement the color selection. We have found no galaxy candidates closer to the QSO than 7" that could be responsible for the damped Ly{alpha} systems. Assuming that at least one of the galaxies is not directly beneath the QSO, we set an upper limit on this damped Ly {alpha} system of L<L^*^_LBG_/4. Finally, we have established a Web site to release these imaging data to the public, at http://kingpin.ucsd.edu/~dlaimg/papers/refern.html . The observations where made with LRIS on the Keck II telescope, on 13 Jan 1999 for PSS 0132+1341 and BR 0951-0450, and 23 Jan 1999 for PSS 1443+2724.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+AS/118/65
- Title:
- BRI & redshifts in Cl0939+472 & Cl0016+161
- Short Name:
- J/A+AS/118/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a study of the galaxy population of Cl 0939+472 (z=0.41) and Cl 0016+161 (z=0.54). We have used narrow-band filters (FWHM=~90-200A) and broad band B, R, I filters covering the range from 3800A to 9200A obtain low resolution spectra for all galaxies brighter than R=22.5mag in a 5'x5' (Cl 0939+472) and a 3.5'x5' (Cl 0016+161) field. Template spectra for classical Hubble type and E+A galaxies were fitted to the low-resolution spectral energy distribution in order to determine the galaxies' redshift and the morphological type. We detected 160 cluster members in Cl 0939+472 and 100 in Cl 0016+161, with a success rate of about 80% in the determination of redshifts and corresponding classification of morphological types from spectral energy distributions. These results constitute a statistical improvement of at least a factor of 4 over the most complete study to date of these clusters. In particular, we provide a large sample of elliptical galaxies with secure membership, well suited for a study of evolutionary effects. The same E+A templates developed for the analysis of Cl 0939+472 were successful in recognizing almost all of the spectroscopically already known E+A galaxies in Cl 0016+161 and in identifying 10 new ones. Our results show that in this cluster, too, the fraction of E+A galaxies represents about 20% of the total galaxy population. This outlines the importance of taking into account galaxies with signs of recent star formation for a correct evaluation of the Butcher-Oemler effect in distant galaxy clusters.
- ID:
- ivo://CDS.VizieR/J/A+A/561/L8
- Title:
- BRJK photometry of Seyfert galaxy WPVS48
- Short Name:
- J/A+A/561/L8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using robotic telescopes of the Universitatssternwarte Bochum near Cerro Armazones in Chile, we monitored the z=0.0377 Seyfert 1 galaxy WPVS48 in the optical (B and R) and near-infrared (NIR, J and K) with a cadence of two days.
- ID:
- ivo://CDS.VizieR/J/A+A/579/A113
- Title:
- BR light curves of GJ1214b
- Short Name:
- J/A+A/579/A113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The atmospheric composition and vertical structure of the super-Earth GJ 1214b has been a subject of debate since its discovery in 2009. Recent studies have indicated that high-altitude clouds might mask the lower layers. However, some data points that were gathered at different times and facilities do not fit this picture, probably because of a combination of stellar activity and systematic errors. We observed two transits of GJ 1214b with the Large Binocular Camera, the dual-channel camera at the Large Binocular Telescope. For the first time, we simultaneously measured the relative planetary radius k=R_p_/R_*_ at blue and red optical wavelengths (B+R), thus constraining the Rayleigh scattering on GJ 1214b after correcting for stellar activity effects. To the same purpose, a long-term photometric follow-up of the host star was carried out with WiFSIP at STELLA, revealing a rotational period that is significantly longer than previously reported. Our new unbiased estimates of k yield a flat transmission spectrum extending to shorter wavelengths, thus confirming the cloudy atmosphere scenario for GJ 1214b.
- ID:
- ivo://CDS.VizieR/J/A+AS/124/283
- Title:
- BR magnitude and redshift of A1300
- Short Name:
- J/A+AS/124/283
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results of an optical follow-up of X-ray bright clusters of galaxies located between 0.15<=z<=0.31: B and R photometry as well as medium resolution spectroscopy of the galaxies. The cluster studied here - A1300 - is found to have a redshift of 0.3072 and a velocity dispersion of 1210km/s, based on 52 cluster members. Structures are observed in the galaxy number counts but the velocity histogram shows no significant departure from a Gaussian distribution.
- ID:
- ivo://CDS.VizieR/J/AJ/125/1711
- Title:
- Broad Absorption Line Quasars from SDSS
- Short Name:
- J/AJ/125/1711
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 224 broad absorption line quasars (BALQSOs) from the Sloan Digital Sky Survey's Early Data Release Quasar Catalog, (Schneider et al., 2002, Cat. <J/AJ/123/567>) including a relatively complete and homogeneous subsample of 131 BALQSOs. Since the identification of BALQSOs is subject to considerable systematic uncertainties, we attempt to create a complete sample of SDSS BALQSOs by combining the results of two automated selection algorithms and a by-eye classification scheme. One of these automated algorithms finds broad absorption line troughs by comparing with a composite quasar spectrum. We present the details of this algorithm and compare this method with one that uses a power-law fit to the continuum. The BALQSOs in our sample are further classified as high-ionization BALQSOs (HiBALs), low-ionization BALQSOs (LoBALs), and BALQSOs with excited iron absorption features (FeLoBALs); composite spectra of each type are presented. We further present a study of the properties of the BALQSOs in terms of the balnicity distribution, which rises with decreasing balnicity. This distribution of balnicities suggests that the fraction of quasars with intrinsic outflows may be significantly underestimated. The balnicity index defined by Weymann et al. (1991ApJ...373...23W) amounts to a sort of equivalent width: a quasar is declared to be a BAL when its balnicity index is >=0.
- ID:
- ivo://CDS.VizieR/J/A+A/622/A15
- Title:
- Broad absorption line quasars in LDR1
- Short Name:
- J/A+A/622/A15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the low-frequency radio properties of broad absorption line quasars (BALQSOs) from the LOFAR Two-metre Sky-Survey Data Release 1 (LDR1). The value-added LDR1 catalogue contains Pan-STARRS counterparts, which we match with the Sloan Digital Sky Survey (SDSS) DR7 and DR12 quasar catalogues. We find that BALQSOs are twice as likely to be detected at 144MHz than their non-BAL counterparts, and BALQSOs with low-ionisation species present in their spectra are three times more likely to be detected than those with only high-ionisation species. The BALQSO fraction at 144MHz is constant with increasing radio luminosity, which is inconsistent with previous results at 1.4GHz, indicating that observations at the different frequencies may be tracing different sources of radio emission. We cross-match radio sources between the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) survey and LDR1, which provides a bridge via the LDR1 Pan-STARRS counterparts to identify BALQSOs in SDSS. Consequently we expand the sample of BALQSOs detected in FIRST by a factor of three. The LDR1-detected BALQSOs in our sample are almost exclusively radio-quiet (logr<2), with radio sizes at 144$\,$MHz typically less than 200kpc these radio sizes tend to be larger than those at 1.4GHz, suggesting more extended radio emission at low frequencies. We find that although the radio detection fraction increases with increasing balnicity index (BI), there is no correlation between BI and either low-frequency radio power or radio-loudness. This suggests that both radio emission and BI may be linked to the same underlying process, but are spatially distinct phenomena.
- ID:
- ivo://CDS.VizieR/J/AJ/153/149
- Title:
- Broadband photometry of Neptune from K2
- Short Name:
- J/AJ/153/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report here on our search for excess power in photometry of Neptune collected by the K2 mission that may be due to intrinsic global oscillations of the planet Neptune. To conduct this search, we developed new methods to correct for instrumental effects such as intrapixel variability and gain variations. We then extracted and analyzed the time-series photometry of Neptune from 49 days of nearly continuous broadband photometry of the planet. We find no evidence of global oscillations and place an upper limit of ~5ppm at 1000{mu}Hz for the detection of a coherent signal. With an observed cadence of 1 minute and a point-to-point scatter of less than 0.01%, the photometric signal is dominated by reflected light from the Sun, which is in turn modulated by atmospheric variability of Neptune at the 2% level. A change in flux is also observed due to the increasing distance between Neptune and the K2 spacecraft and the solar variability with convection-driven solar p modes present.
- ID:
- ivo://CDS.VizieR/J/A+A/384/504
- Title:
- Broadband polarimetry of novae in outburst
- Short Name:
- J/A+A/384/504
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present broadband optical polarimetry of the classical novae V705 Cas, V4362 Sgr, V2313 Oph and BY Cir in outburst. The data indicate that, in all cases, there is an intrinsic component of polarization and in some cases the variability is very rapid, on a time-scale ~1day. In the case of V705 Cas, we suggest that the origin of the intrinsic component may lie in the clumpiness and/or inhomogeneities of the ejecta, while electron scattering is the most likely cause in V2313 Oph. The wavelength-dependence of polarization in the case of V4362 Sgr suggests scattering by small dust grains, while polarization in resonance lines is the most probable cause of the observed polarization in BY Cir.
- ID:
- ivo://CDS.VizieR/J/MNRAS/469/4034
- Title:
- Broadband polarisation of radio AGN
- Short Name:
- J/MNRAS/469/4034
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from a broadband (1 to 3GHz), spectro-polarimetry study of the integrated emission from 100 extragalactic radio sources with the ATCA, selected to be highly linearly polarized at 1.4 GHz. We use a general purpose, polarization model-fitting procedure that describes the Faraday rotation measure (RM) and intrinsic polarization structure of up to three distinct polarized emission regions or 'RM components' of a source. Overall, 37%/52%/11% of sources are best fit by one/two/three RM components. However, these fractions are dependent on the signal-to-noise ratio (S/N) in polarization (more RM components more likely at higher S/N). In general, our analysis shows that sources with high integrated degrees of polarization at 1.4GHz have low Faraday depolarization, are typically dominated by a single RM component, have a steep spectral index, and a high intrinsic degree of polarization. After classifying our sample into radiative-mode and jet-mode AGN, we find no significant difference between the Faraday rotation or Faraday depolarization properties of jet-mode and radiative-mode AGN. However, there is a statistically significant difference in the intrinsic degree of polarization between the two types, with the jet-mode sources having more intrinsically ordered magnetic field structures than the radiative-mode sources. We also find a preferred perpendicular orientation of the intrinsic magnetic field structure of jet-mode AGN with respect to the jet direction, while no clear preference is found for the radiative-mode sources.
