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- ID:
- ivo://CDS.VizieR/J/A+A/632/A85
- Title:
- PSF photometric catalog of VVV survey data
- Short Name:
- J/A+A/632/A85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Vista Variables in the Via Lactea (VVV) survey has performed a multi-epoch near-infrared imaging of the inner Galactic plane. High-fidelity photometric catalogs are needed to utilize the data. We aim at producing a deep, point-spread-function (PSF) photometric catalog for the VVV survey J, H, and Ks band data. Specifically, we aim at taking advantage of all the epochs of the survey to reach high limiting magnitudes. We develop an automatic PSF-fitting pipeline based on the DaoPHOT algorithm and perform photometry on the stacked VVV images in J, H, and Ks bands. We present a PSF photometric catalog in the Vega system that contains about 926 million sources in the J, H, and Ks filters. About 10% of the sources are flagged as possible spurious detections. The 5 sigma limiting magnitudes of the sources with high reliability are about 20.8, 19.5, and 18.7mag in the J, H, and Ks band, respectively, depending on the local crowding condition. Our photometric catalog reaches on average about one magnitude deeper than the previously released PSF DoPHOT photometric catalog. It also includes less spurious detections. There are significant differences in the brightnesses of faint sources between our catalog and the previously released one. The likely origin of these differences is in the different photometric algorithms that are utilized; it is not straightforward to assess which catalog is more accurate in which situations. Our new catalog is beneficial especially for science goals that require high limiting magnitudes; our catalog reaches such in fields that have a relatively uniform source number density. Overall, the limiting magnitudes and completeness are different in the fields with different crowding conditions.
- ID:
- ivo://CDS.VizieR/J/AJ/159/25
- Title:
- PS1 light curves and rotation periods of new asteroids
- Short Name:
- J/AJ/159/25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The intranight trajectories of asteroids can be approximated by straight lines, and so are their intranight detections. Therefore, the Hough transform, a line detecting algorithm, can be used to connect the line-up detections to find asteroids. We applied this algorithm to a high-cadence Pan-STARRS 1 (PS1) observation, which was originally designed to collect asteroid light curves for rotation period measurements. The algorithm recovered most of the known asteroids in the observing fields and, moreover, discovered 3574 new asteroids with magnitude mainly of 21.5<w_p1_<22.5mag. This magnitude range is equivalent to subkilometer main-belt asteroids (MBAs), which usually lack rotation period measurements due to their faintness. Using the light curves of the 3574 new asteroids, we obtained 122 reliable rotation periods, of which 13 are super-fast rotators (SRFs; i.e., rotation period of <2hr). The required cohesion to survive these SFRs range from tens to thousands of Pa, a value consistent with the known SFRs and the regolith on the Moon and Mars. The higher chance of discovering SFRs here suggests that subkilometer MBAs probably harbor more SFRs.
- ID:
- ivo://nasa.heasarc/skyview/pspc0.6int
- Title:
- PSPC summed pointed observations, 0.6 degree cutoff, Intensity
- Short Name:
- PSPC0.6Int
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ROSAT PSPC surveys were generated by <i> SkyView </i> as mosaics from publically available PSPC observations. The surveys include all data available through March 1, 1997. This includes the vast majority of ROSAT PSPC observations. Filter observations and observations taken during the verification phase in 1991 were not included in either set. The details of the generation of the surveys are discussed in a <a href="https://skyview.gsfc.nasa.gov/help/pspc_generation.html"> companion document</a>. Basically the counts and exposure from all observations were added and then an intensity map was generated as the ratio of the two. <p> The smaller cut-offs allow users to distinguish point sources in fields where a bright source may have been towards the edge of one observation and near the center of another. In these cases the source appears fuzzy due to the poor resolution of ROSAT near the edge of the field of view. This comes at the cost of a substantial reduction in the fraction of the sky covered. Counts and exposure maps are included for users who may need this information (<i>e.g.</i>, to do statistical analysis). <p> The global organization of the surveys is similar to the IRAS survey. Each map covers an area of 2.5&#176;;x2.5&#176;; with a minimum overlap of 0.25&#176;;. To cover the entire sky would require over 10,000 maps. However due to lack of coverage only approximately 4000-6000 maps are actually populated. Users asking for reqions where there is no ROSAT coverage may get a blank region returned. <p> Detailed information regarding the creation of the ROSAT suveys can be found in the <a href="https://skyview.gsfc.nasa.gov/help/pspc_generation.html"> ROSAT PSPC Generation Document</a>. Provenance: Observational data from NASA Goddard Space Flight Center, mosaicking of images done by <i>SkyView</i>.. This is a service of NASA HEASARC.
- ID:
- ivo://nasa.heasarc/skyview/pspc2
- Title:
- PSPC summed pointed observations, 2 degree cutoff, Intensity
- Short Name:
- PSPC2
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ROSAT PSPC surveys were generated by <i> SkyView </i> as mosaics from publically available PSPC observations. The surveys include all data available through March 1, 1997. This includes the vast majority of ROSAT PSPC observations. Filter observations and observations taken during the verification phase in 1991 were not included in either set. The details of the generation of the surveys are discussed in a <a href="https://skyview.gsfc.nasa.gov/help/pspc_generation.html"> companion document</a>. Basically the counts and exposure from all observations were added and then an intensity map was generated as the ratio of the two. <p> The smaller cut-offs allow users to distinguish point sources in fields where a bright source may have been towards the edge of one observation and near the center of another. In these cases the source appears fuzzy due to the poor resolution of ROSAT near the edge of the field of view. This comes at the cost of a substantial reduction in the fraction of the sky covered. Counts and exposure maps are included for users who may need this information (<i>e.g.</i>, to do statistical analysis). <p> The global organization of the surveys is similar to the IRAS survey. Each map covers an area of 2.5&#176;;x2.5&#176;; with a minimum overlap of 0.25&#176;;. To cover the entire sky would require over 10,000 maps. However due to lack of coverage only approximately 4000-6000 maps are actually populated. Users asking for reqions where there is no ROSAT coverage may get a blank region returned. <p> Detailed information regarding the creation of the ROSAT suveys can be found in the <a href="https://skyview.gsfc.nasa.gov/help/pspc_generation.html"> ROSAT PSPC Generation Document</a>. Provenance: Observational data from NASA Goddard Space Flight Center, mosaicking of images done by <i>SkyView</i>.. This is a service of NASA HEASARC.
- ID:
- ivo://nasa.heasarc/skyview/pspc1
- Title:
- PSPC summed pointed observations, 1 degree cutoff, Intensity
- Short Name:
- PSPC1
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ROSAT PSPC surveys were generated by <i> SkyView </i> as mosaics from publically available PSPC observations. The surveys include all data available through March 1, 1997. This includes the vast majority of ROSAT PSPC observations. Filter observations and observations taken during the verification phase in 1991 were not included in either set. The details of the generation of the surveys are discussed in a <a href="https://skyview.gsfc.nasa.gov/help/pspc_generation.html"> companion document</a>. Basically the counts and exposure from all observations were added and then an intensity map was generated as the ratio of the two. <p> The smaller cut-offs allow users to distinguish point sources in fields where a bright source may have been towards the edge of one observation and near the center of another. In these cases the source appears fuzzy due to the poor resolution of ROSAT near the edge of the field of view. This comes at the cost of a substantial reduction in the fraction of the sky covered. Counts and exposure maps are included for users who may need this information (<i>e.g.</i>, to do statistical analysis). <p> The global organization of the surveys is similar to the IRAS survey. Each map covers an area of 2.5&#176;;x2.5&#176;; with a minimum overlap of 0.25&#176;;. To cover the entire sky would require over 10,000 maps. However due to lack of coverage only approximately 4000-6000 maps are actually populated. Users asking for reqions where there is no ROSAT coverage may get a blank region returned. <p> Detailed information regarding the creation of the ROSAT suveys can be found in the <a href="https://skyview.gsfc.nasa.gov/help/pspc_generation.html"> ROSAT PSPC Generation Document</a>. Provenance: Observational data from NASA Goddard Space Flight Center, mosaicking of images done by <i>SkyView</i>.. This is a service of NASA HEASARC.
- ID:
- ivo://CDS.VizieR/J/ApJ/850/96
- Title:
- PS1 3{pi} RRab stars within the Sgr stream
- Short Name:
- J/ApJ/850/96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive and precise description of the Sagittarius (Sgr) stellar stream's 3D geometry as traced by its old stellar population. This analysis draws on the sample of ~44000 RR Lyrae (RRab) stars from the Pan-STARRS1 (PS1) 3{pi} survey, which is ~80% complete and ~90% pure within 80 kpc, and extends to >~120kpc with a distance precision of ~3% . A projection of RR Lyrae stars within |^~^B|_{sun}_<9{deg} of the Sgr stream's orbital plane reveals the morphology of both the leading and the trailing arms at very high contrast across much of the sky. In particular, the map traces the stream near- contiguously through the distant apocenters. We fit a simple model for the mean distance and line-of-sight depth of the Sgr stream as a function of the orbital plane angle ^~^{Lambda}_{sun}_, along with a power-law background model for the field stars. This modeling results in estimates of the mean stream distance precise to ~1% and it resolves the stream's line-of-sight depth. These improved geometric constraints can serve as new constraints for dynamical stream models.
- ID:
- ivo://CDS.VizieR/J/ApJ/858/41
- Title:
- PS1 proper-motion survey for brown dwarfs. I. Taurus
- Short Name:
- J/ApJ/858/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We are conducting a proper-motion survey for young brown dwarfs in the Taurus-Auriga molecular cloud based on the Pan-STARRS1 3{pi} Survey. Our search uses multi-band photometry and astrometry to select candidates, and is wider (370deg^2^) and deeper (down to ~3M_Jup_) than previous searches. We present here our search methods and spectroscopic follow-up of our high-priority candidates. Since extinction complicates spectral classification, we have developed a new approach using low-resolution (R~100) near-infrared spectra to quantify reddening-free spectral types, extinctions, and gravity classifications for mid-M to late-L ultracool dwarfs (<=100-3M_Jup_ in Taurus). We have discovered 25 low-gravity (VL-G) and the first 11 intermediate-gravity (INT-G) substellar (M6-L1) members of Taurus, constituting the largest single increase of Taurus brown dwarfs to date. We have also discovered 1 new Pleiades member and 13 new members of the Perseus OB2 association, including a candidate very wide separation (58kau) binary. We homogeneously reclassify the spectral types and extinctions of all previously known Taurus brown dwarfs. Altogether our discoveries have thus far increased the substellar census in Taurus by ~40% and added three more L-type members (<~5-10M_Jup_). Most notably, our discoveries reveal an older (>10Myr) low-mass population in Taurus, in accord with recent studies of the higher-mass stellar members. The mass function appears to differ between the younger and older Taurus populations, possibly due to incompleteness of the older stellar members or different star formation processes.
- ID:
- ivo://CDS.VizieR/J/ApJ/795/44
- Title:
- PS1 SNe Ia (0.02<z<0.7) griz light curves
- Short Name:
- J/ApJ/795/44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present griz_P1_ light curves of 146 spectroscopically confirmed Type Ia supernovae (SNe Ia; 0.03<z<0.65) discovered during the first 1.5yr of the Pan-STARRS1 Medium Deep Survey. The Pan-STARRS1 natural photometric system is determined by a combination of on-site measurements of the instrument response function and observations of spectrophotometric standard stars. We find that the systematic uncertainties in the photometric system are currently 1.2% without accounting for the uncertainty in the Hubble Space Telescope Calspec definition of the AB system. A Hubble diagram is constructed with a subset of 113 out of 146 SNe Ia that pass our light curve quality cuts. The cosmological fit to 310 SNe Ia (113 PS1 SNe Ia + 222 light curves from 197 low-z SNe Ia), using only supernovae (SNe) and assuming a constant dark energy equation of state and flatness, yields {omega}=-1.120_-0.206_^+0.360^(Stat)_-0.291_^+0.269^(Sys). When combined with BAO+CMB(Planck)+H_0_, the analysis yields {Omega}_M_=0.280_-0.012_^+0.013^ and {omega}=-1.166_-0.069_^+0.072^ including all identified systematics. The value of w is inconsistent with the cosmological constant value of -1 at the 2.3{sigma} level. Tension endures after removing either the baryon acoustic oscillation (BAO) or the H_0_ constraint, though it is strongest when including the H_0_ constraint. If we include WMAP9 cosmic microwave background (CMB) constraints instead of those from Planck, we find {omega}=-1.124_-0.065_^+0.083^, which diminishes the discord to <2{sigma}. We cannot conclude whether the tension with flat {Lambda}CDM is a feature of dark energy, new physics, or a combination of chance and systematic errors. The full Pan-STARRS1 SN sample with ~three times as many SNe should provide more conclusive results.
- ID:
- ivo://CDS.VizieR/J/AJ/154/129
- Title:
- PSYM-WIDE: planetary-mass companions to YMG members
- Short Name:
- J/AJ/154/129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a direct imaging survey for very large separation (>100 AU), low-mass companions around 95 nearby young K5-L5 stars and brown dwarfs. They are high-likelihood candidates or confirmed members of the young (~<150 Myr) {beta} Pictoris and AB Doradus moving groups (ABDMG) and the TW Hya, Tucana-Horologium, Columba, Carina, and Argus associations. Images in i' and z' filters were obtained with the Gemini Multi-Object Spectrograph (GMOS) on Gemini South to search for companions down to an apparent magnitude of z'~22-24 at separations >~20" from the targets and in the remainder of the wide 5.5'x5.5' GMOS field of view. This allowed us to probe the most distant region where planetary-mass companions could be gravitationally bound to the targets. This region was left largely unstudied by past high-contrast imaging surveys, which probed much closer-in separations. This survey led to the discovery of a planetary-mass (9-13 M_Jup_) companion at 2000 AU from the M3V star GU Psc, a highly probable member of ABDMG. No other substellar companions were identified. These results allowed us to constrain the frequency of distant planetary-mass companions (5-13 M_Jup_) to 0.84_-0.66_^+6.73^% (95% confidence) at semimajor axes between 500 and 5000 AU around young K5-L5 stars and brown dwarfs. This is consistent with other studies suggesting that gravitationally bound planetary-mass companions at wide separations from low-mass stars are relatively rare.
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