We present PHIBSS, the IRAM Plateau de Bure high-z blue sequence CO(3-2) survey of the molecular gas properties in massive, main-sequence star-forming galaxies (SFGs) near the cosmic star formation peak. PHIBSS provides 52 CO detections in two redshift slices at z~1.2 and 2.2, with log(M_*_(M_{sun}_))>=10.4 and log(SFR(M_{sun}_/yr))>=1.5. Including a correction for the incomplete coverage of the M_*_-SFR plane, and adopting a "Galactic" value for the CO-H_2_ conversion factor, we infer average gas fractions of ~0.33 at z~1.2 and ~0.47 at z~2.2. Gas fractions drop with stellar mass, in agreement with cosmological simulations including strong star formation feedback. Most of the z~1-3 SFGs are rotationally supported turbulent disks. The sizes of CO and UV/optical emission are comparable. The molecular-gas-star-formation relation for the z=1-3 SFGs is near-linear, with a ~0.7Gyr gas depletion timescale; changes in depletion time are only a secondary effect. Since this timescale is much less than the Hubble time in all SFGs between z~0 and 2, fresh gas must be supplied with a fairly high duty cycle over several billion years. At given z and M_*_, gas fractions correlate strongly with the specific star formation rate (sSFR). The variation of sSFR between z~0 and 3 is mainly controlled by the fraction of baryonic mass that resides in cold gas.
The presence of heavier chemical elements in stellar atmospheres influences the spectral energy distribution of stars. An uneven surface distribution of these elements, together with flux redistribution and stellar rotation, are commonly believed to be the primary causes of the variability of chemically peculiar (CP) stars. We aim to model the photometric variability of the CP star phi Dra based on the assumption of inhomogeneous surface distribution of heavier elements and compare it to the observed variability of the star. We also intend to identify the processes that contribute most significantly to its photometric variability. We use a grid of TLUSTY model atmospheres and the SYNSPEC code to model the radiative flux emerging from the individual surface elements of phi Dra with different chemical compositions. We integrate the emerging flux over the visible surface of the star at different phases throughout the entire rotational period to synthesise theoretical light curves of the star in several spectral bands.
The Phoenix Deep Survey is a multiwavelength galaxy survey based on deep 1.4GHz radio imaging. The primary goal of this survey is to investigate the properties of star formation in galaxies and to trace the evolution in those properties to a redshift z=1, covering a significant fraction of the age of the universe. By compiling a sample of star-forming galaxies based on selection at radio wavelengths we eliminate possible biases due to dust obscuration, a significant issue when selecting objects at optical and ultraviolet wavelengths. In this paper, we present the catalogs and results of deep optical (UBVRI) and near-infrared (Ks) imaging of the deepest region of the existing decimetric radio imaging. The observations and data processing are summarized and the construction of the optical source catalogs described, together with the details of the identification of candidate optical counterparts to the radio catalogs. Based on our UBVRIKs imaging, photometric redshift estimates for the optical counterparts to the radio detections are explored.
Phot and Spectrophot Investigation, South Gal Pole
Short Name:
II/120
Date:
21 Oct 2021
Publisher:
CDS
Description:
Photoelectric magnitudes and colors in the Johnson-Morgan UBV system for 477 stars in 6 square degrees near Kapteyn Selected Area 141 (l=245, b=-86; 00 43 < RA < 01 11, -33.7 < Dec < -26.9, B1950.0) are given in the first data file. The estimated rms accuracies are 0.02 (V), 0.03 (B-V), 0.07 (U-B) for stars in the magnitude range 15 to 16. Table 2 of the source reference gives the mean errors for intervals of magnitude. Photographic V magnitudes and B-V colors are given for 2835 stars to magnitude 17 (in the same region as above) in the second data file. The estimated rms accuracies are 0.05 (V) and 0.08 (B-V). The mean errors of the computed right ascensions and declinations are 0.15s and 2", respectively.
All measurements in the literature on the Cape photometric system as of early 1975 have been compiled. The catalog includes measurements from 38 publications as well as 469 unpublished measurements forwarded by Dr. A. W. J. Cousins.
Photoelectric observations of Cepheids in UBV(RI)c
Short Name:
II/285
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog gathers the observation of 894 Cepheids made between 1986 to 2004. Observations are listed in alphabetical order of the constellations. The standard deviation for every magnitude and color is 0.01mag. This version supersedes the 1997 edition (Cat. <II/217>)
The catalog is a compilation of photoelectric photometry in the Johnson UBVRI system published prior to mid-1984. The catalog contains a total of 6849 stars in the original Johnson system (Morel and Magnenat 1978), 467 stars in the system of Kunkel and Rydgren (1979), 1150 stars in the system of Moffett and Barnes III (1979), and 252 stars in the system of Neckel and Chini (1980). The catalog is in 14 files: The first 12 files list observational data, mean values, and references for each of the four standard systems. An additional two files contain the numbering scheme of Mermilliod (1978) used to identify objects, and introductory information.
Photoelectric UBV photometry is presented for a sample of 165 stars drawn from the extension of the HK objective-prism/interference-filter survey of Beers, Preston and Shectman (1985AJ.....90.2089B) to the northern galactic hemisphere. These results are part of continuing follow-up observations of candidate metal-deficient and horizontal-branch field stars and other interesting stars identified in the survey. A complete set of photometric observations is now available for three of the 25-square-degree survey fields. We estimate that the complete photometric sample of 299 northern HK candidates obtained to date contains on order 90 main-sequences turnoff, subgiant, and giant stars with [Fe/H]<=-1.0, 50 field blue horizontal-branch stars, and 30 stars with the photometric properties of field blue stragglers.
