Search

Start Over Subject optical astronomy Capability Type Simple Cone Search
1971. Period of M15 variable stars
ID:
ivo://CDS.VizieR/J/AJ/135/1459
Title:
Period of M15 variable stars
Short Name:
J/AJ/135/1459
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present new BVI CCD photometry for variables in the globular cluster M15. Our photometry was obtained using both the image subtraction package ISIS and DAOPHOT/ALLFRAME. The data were acquired in 2001 on two observing runs on 11 observing nights using the 2m telescope of the Bulgarian National Astronomical Observatory "Rozhen" with a Photometrics CCD camera. For 39 previously known variables, we present a period for the first time, and improved periods were obtained for many previously known variables. Fourteen new variables are reported. We present updated Bailey diagrams for the cluster, and discuss its Oosterhoff classification. Although many of M15's RRab pulsators fall at an intermediate locus between Oosterhoff types I and II (OoII) in the Bailey diagram, we argue that M15 is indeed a bona fide OoII globular cluster.
1972. PESSTO catalog
ID:
ivo://CDS.VizieR/J/A+A/579/A40
Title:
PESSTO catalog
Short Name:
J/A+A/579/A40
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Public European Southern Observatory Spectroscopic Survey of Transient Objects (PESSTO) began as a public spectroscopic survey in April 2012. PESSTO classifies transients from publicly available sources and wide-field surveys, and selects science targets for detailed spectroscopic and photometric follow-up. PESSTO runs for nine months of the year, January - April and August - December inclusive, and typically has allocations of 10 nights per month. We describe the data reduction strategy and data products that are publicly available through the ESO archive as the Spectroscopic Survey data release 1 (SSDR1). PESSTO uses the New Technology Telescope with the instruments EFOSC2 and SOFI to provide optical and NIR spectroscopy and imaging. We target supernovae and optical transients brighter than 20.5^m^ for classification. Science targets are selected for follow-up based on the PESSTO science goal of extending knowledge of the extremes of the supernova population. We use standard EFOSC2 set-ups providing spectra with resolutions of 13-18{AA} between 3345-9995{AA}. A subset of the brighter science targets are selected for SOFI spectroscopy with the blue and red grisms (0.935-2.53{mu}m and resolutions 23-33{AA}) and imaging with broadband JHK_s_ filters. This first data release (SSDR1) contains flux calibrated spectra from the first year (April 2012-2013). A total of 221 confirmed supernovae were classified, and we released calibrated optical spectra and classifications publicly within 24h of the data being taken (via WISeREP). The data in SSDR1 replace those released spectra. They have more reliable and quantifiable flux calibrations, correction for telluric absorption, and are made available in standard ESO Phase 3 formats. We estimate the absolute accuracy of the flux calibrations for EFOSC2 across the whole survey in SSDR1 to be typically ~15%, although a number of spectra will have less reliable absolute flux calibration because of weather and slit losses. Acquisition images for each spectrum are available which, in principle, can allow the user to refine the absolute flux calibration. The standard NIR reduction process does not produce high accuracy absolute spectrophotometry but synthetic photometry with accompanying JHK_s_ imaging can improve this. Whenever possible, reduced SOFI images are provided to allow this. Future data releases will focus on improving the automated flux calibration of the data products. The rapid turnaround between discovery and classification and access to reliable pipeline processed data products has allowed early science papers in the first few months of the survey.
1973. PHANGS-MUSE sample HII regions catalog
ID:
ivo://CDS.VizieR/J/A+A/658/A188
Title:
PHANGS-MUSE sample HII regions catalog
Short Name:
J/A+A/658/A188
Date:
02 Mar 2022 06:10:18
Publisher:
CDS
Description:
We use an unprecedented sample of about 23000 HII regions detected at an average physical resolution of 67pc in the PHANGS-MUSE sample to study the extragalactic HII region H{alpha} luminosity function (LF). Our observations probe the star-forming disk of 19 nearby spiral galaxies with low inclination and located close to the star formation main sequence at z=0. The mean LF slope in our sample is =1.73 with a {sigma} of 0.15. We find that {alpha} decreases with the galaxy's star formation rate surface density {SIGMA}_SFR_ and argue that this is driven by an enhanced clustering of young stars at high gas surface densities. Looking at the HII regions within single galaxies we find that no significant variations occur between the LF of the inner and outer part of the star-forming disk, whereas the LF in the spiral arm areas is shallower than in the inter-arm areas for six out of the 13 galaxies with clearly visible spiral arms. We attribute these variations to the spiral arms increasing the molecular clouds arm-inter-arm mass contrast and find suggestive evidence that they are more evident for galaxies with stronger spiral arms. Furthermore, we find systematic variations in {alpha} between samples of HII regions with high and low ionization parameter q and argue that they are driven by the aging of HII regions.
1974. PHAT stellar cluster survey. I. Year 1
ID:
ivo://CDS.VizieR/J/ApJ/752/95
Title:
PHAT stellar cluster survey. I. Year 1
Short Name:
J/ApJ/752/95
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Panchromatic Hubble Andromeda Treasury (PHAT) survey is an ongoing Hubble Space Telescope (HST) multi-cycle program to obtain high spatial resolution imaging of one-third of the M31 disk at ultraviolet through near-infrared wavelengths. In this paper, we present the first installment of the PHAT stellar cluster catalog. When completed, the PHAT cluster catalog will be among the largest and most comprehensive surveys of resolved star clusters in any galaxy. The exquisite spatial resolution achieved with HST has allowed us to identify hundreds of new clusters that were previously inaccessible with existing ground-based surveys. We identify 601 clusters in the Year 1 sample, representing more than a factor of four increase over previous catalogs within the current survey area (390 arcmin^2^). This work presents results derived from the first ~25% of the survey data; we estimate that the final sample will include ~2500 clusters. For the Year 1 objects, we present a catalog with positions, radii, and six-band integrated photometry. Along with a general characterization of the cluster luminosities and colors, we discuss the cluster luminosity function, the cluster size distributions, and highlight a number of individually interesting clusters found in the Year 1 search.
1975. PHIBSS: CO observations of star-forming galaxies
ID:
ivo://CDS.VizieR/J/ApJ/768/74
Title:
PHIBSS: CO observations of star-forming galaxies
Short Name:
J/ApJ/768/74
Date:
21 Oct 2021
Publisher:
CDS
Description:
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.
1976. Phoenix Deep Survey: optical and NIR catalogs
ID:
ivo://CDS.VizieR/J/ApJS/155/1
Title:
Phoenix Deep Survey: optical and NIR catalogs
Short Name:
J/ApJS/155/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
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.
1977. Phot and Spectrophot Investigation, South Gal Pole
ID:
ivo://CDS.VizieR/II/120
Title:
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.
1978. Photoelectric measurements in UcBV system
ID:
ivo://CDS.VizieR/II/27
Title:
Photoelectric measurements in UcBV system
Short Name:
II/27
Date:
21 Oct 2021
Publisher:
CDS
Description:
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.
1979. Photoelectric observations of Cepheids in UBV(RI)c
ID:
ivo://CDS.VizieR/II/285
Title:
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>)
1980. Photoelectric observations of Cepheids in UBV(RI)c
ID:
ivo://CDS.VizieR/II/217
Title:
Photoelectric observations of Cepheids in UBV(RI)c
Short Name:
II/217
Date:
21 Oct 2021
Publisher:
CDS
Description:
Observations are listed in alphabetical order of the constellations. The standard deviation for every magnitude and color is 0.01 mag.