- ID:
- ivo://CDS.VizieR/J/ApJ/804/7
- Title:
- SaMOSA: optical spectroscopy of 7 Fermi blazars
- Short Name:
- J/ApJ/804/7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multi-epoch optical spectroscopy of seven southern Fermi-monitored blazars from 2008 to 2013 using the Small and Medium Aperture Research Telescope System (SMARTS), with supplemental spectroscopy and polarization data from the Steward Observatory. We find that the emission lines are much less variable than the continuum; four of seven blazars had no detectable emission line variability over the 5 yr observation period. This is consistent with photoionization primarily by an accretion disk, allowing us to use the lines as a probe of disk activity. Comparing optical emission line flux with Fermi {gamma}-ray flux and optical polarized flux, we investigate whether relativistic jet variability is related to the accretion flow. In general, we see no such dependence, suggesting that the jet variability is likely caused by internal processes like turbulence or shock acceleration rather than a variable accretion rate. However, three sources showed statistically significant emission line flares in close temporal proximity to very large Fermi {gamma}-ray flares. While we do not have sufficient emission line data to quantitatively assess their correlation with the {gamma}-ray flux, it appears that in some cases the jet might provide additional photoionizing flux to the broad-line region (BLR), which implies that some {gamma}-rays are produced within the BLR, at least for these large flares.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/468/163
- Title:
- Sample of low mass stars with mu>0.1"/yr
- Short Name:
- J/A+A/468/163
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present details of the second part of the Southern Infrared Proper Motion Survey (SIPS). Here accurate relative astrometry allows us to reduce the minimum proper motion to 0.1"/yr. This yields 6904 objects with proper motions between our minimum cut and half an arcsecond a year. A small overspill sample with proper motions greater than this is also included. We examine our sample to identify interesting individual objects such as common proper motion binaries, potential L dwarfs and candidate nearby stars. Finally we show our survey is incomplete due to many factors, factors which we will take into account when simulating these survey results in the next paper in this series.
2553. SBNAF Infrared Database
- ID:
- ivo://CDS.VizieR/J/A+A/635/A54
- Title:
- SBNAF Infrared Database
- Short Name:
- J/A+A/635/A54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present the Small Bodies: Near and Far (SBNAF) Infrared Database, an easy-to-use tool intended to facilitate the modelling of thermal emission of small bodies of the Solar System. Our database collects measurements of thermal emissions for small Solar System targets that are otherwise available in scattered sources and provides a complete description of the data, including all information necessary to perform direct scientific analyses and without the need to access additional external resources. This public database contains representative data of asteroid observations of large surveys (e.g. AKARI, IRAS, and WISE) as well as a collection of small body observations of infrared space telescopes (e.g. the Herschel Space Observatory) and provides a web interface to access this data (https://ird.konkoly.hu).We also provide an example for the direct application of the database and show how it can be used to estimate the thermal inertia of specific populations, e.g. asteroids within a given size range. We show how different scalings of thermal inertia with heliocentric distance (i.e. temperature) may affect our interpretation of the data and discuss why the widely-used radiative conductivity exponent (alpha=-3/4) might not be adequate in general, as suggested in previous studies.
- ID:
- ivo://CDS.VizieR/J/AJ/162/259
- Title:
- Scaling K2. IV. Campaigns 1-8 & 10-18 planets sample
- Short Name:
- J/AJ/162/259
- Date:
- 15 Mar 2022
- Publisher:
- CDS
- Description:
- We provide the first full K2 transiting exoplanet sample, using photometry from Campaigns 1-8 and 10-18, derived through an entirely automated procedure. This homogeneous planet candidate catalog is crucial to perform a robust demographic analysis of transiting exoplanets with K2. We identify 747 unique planet candidates and 57 multiplanet systems. Of these candidates, 366 have not been previously identified, including one resonant multiplanet system and one system with two short-period gas giants. By automating the construction of this list, measurements of sample biases (completeness and reliability) can be quantified. We carried out a light-curve-level injection/recovery test of artificial transit signals and found a maximum completeness of 61%, a consequence of the significant detrending required for K2 data analysis. Through this operation we attained measurements of the detection efficiency as a function of signal strength, enabling future population analysis using this sample. We assessed the reliability of our planet sample by testing our vetting software EDI-Vetter against inverted transit-free light curves. We estimate that 91% of our planet candidates are real astrophysical signals, increasing up to 94% when limited to the FGKM dwarf stellar population. We also constrain the contamination rate from background eclipsing binaries to less than 5%. The presented catalog, along with the completeness and reliability measurements, enable robust exoplanet demographic studies to be carried out across the fields observed by the K2 mission for the first time.
- ID:
- ivo://CDS.VizieR/J/ApJ/756/133
- Title:
- ScoCen debris disks around B- and A-type stars
- Short Name:
- J/ApJ/756/133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS) 24 micron and 70 micron observations of 215 nearby, Hipparcos B- and A-type common proper-motion single and binary systems in the nearest OB association, Scorpius-Centaurus. Combining our MIPS observations with those of other ScoCen stars in the literature, we estimate 24 micron B+A-type disk fractions of 17/67 (25^+6^_-5_%), 36/131 (27^+4^_-5_%), and 23/95 (24^+5^_-4_%) for Upper Scorpius (~11Myr), Upper Centaurus Lupus (~15Myr), and Lower Centaurus Crux (~17Myr), respectively, somewhat smaller disk fractions than previously obtained for F- and G-type members. We confirm previous IRAS excess detections and present new discoveries of 51 protoplanetary and debris disk systems, with fractional infrared luminosities ranging from LIR/L*=10^-6^ to 10^-2^ and grain temperatures ranging from Tgr=40 to 300K. In addition, we confirm that the 24 micron and 70 micron excesses (or fractional infrared luminosities) around B+A-type stars are smaller than those measured toward F+G-type stars and hypothesize that the observed disk property dependence on stellar mass may be the result of a higher stellar companion fraction around B- and A-type stars at 10-200AU. Finally, we note that the majority of the ScoCen 24 micron excess sources also possess 12 micron excess, indicating that Earth-like planets may be forming via collisions in the terrestrial planet zone at ~10-100Myr.
- ID:
- ivo://CDS.VizieR/J/ApJ/738/122
- Title:
- ScoCen debris disks Around F- and G-type stars
- Short Name:
- J/ApJ/738/122
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We obtained Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS) 24 micron and 70 micron observations of 182 nearby, Hipparcos F- and G-type common proper motion single and binary systems in the nearest OB association, Scorpius-Centaurus. We also obtained Magellan/MIKE R~50,000 visual spectra at 3500-10500{AA} for 181 candidate ScoCen stars in single and binary systems. Combining our MIPS observations with those of other ScoCen stars in the literature, we estimate 24 micron F+G-type disk fractions of 9/27 (33%+/-11%), 21/67 (31%+/-7%), and 25/71 (35%+/-7%) for Upper Scorpius (~10Myr), Upper Centaurus Lupus (~15Myr), and Lower Centaurus Crux (~17Myr), respectively. We confirm previous IRAS and MIPS excess detections and present new discoveries of 41 protoplanetary and debris disk systems, with fractional infrared luminosities ranging from L_IR/L_*=10^-5^ to 1.0^-2^ and grain temperatures ranging from T_gr_=40-300K. We searched for an increase in 24 micron excess at an age of 15-20Myr, consistent with the onset of debris production predicted by coagulation N-body simulations of outer planetary systems. We found such an increase around 1.5M_{sun}_ stars but discovered a decrease in the 24 micron excess around 1.0M_{sun}_ stars. We additionally discovered that the 24 micron excess around 1.0M_{sun}_ stars is larger than predicted by self-stirred models. Finally, we found a weak anti-correlation between fractional infrared luminosity (L_IR/L_*) and chromospheric activity (R'_HK), that may be the result of differences in stellar HK properties, such as mass, luminosity, and/or winds. We obtained Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS) 24 micron and 70 micron observations of 182 nearby, Hipparcos F- and G-type common proper motion single and binary systems in the nearest OB association, Scorpius-Centaurus. We also obtained Magellan/MIKE R~50,000 visual spectra at 3500-10500{AA} for 181 candidate ScoCen stars in single and binary systems. Combining our MIPS observations with those of other ScoCen stars in the literature, we estimate 24 micron F+G-type disk fractions of 9/27 (33%+/-11%), 21/67 (31%+/-7%), and 25/71 (35%+/-7%) for Upper Scorpius (~10Myr), Upper Centaurus Lupus (~15Myr), and Lower Centaurus Crux (~17Myr), respectively. We confirm previous IRAS and MIPS excess detections and present new discoveries of 41 protoplanetary and debris disk systems, with fractional infrared luminosities ranging from L_IR/L_* = 10^-5^ to 10^-2^ and grain temperatures ranging from T_gr_=40-300K. We searched for an increase in 24 micron excess at an age of 15-20Myr, consistent with the onset of debris production predicted by coagulation N-body simulations of outer planetary systems. We found such an increase around 1.5M_{sun}_ stars but discovered a decrease in the 24 micron excess around 1.0M_{sun}_ stars. We additionally discovered that the 24 micron excess around 1.0M_{sun}_ stars is larger than predicted by self-stirred models.
2557. Sco OB2 association
- ID:
- ivo://CDS.VizieR/J/A+A/382/92
- Title:
- Sco OB2 association
- Short Name:
- J/A+A/382/92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To investigate the dependence of (visual) binarity characteristics on the primary component mass, we selected all stars of spectral type B in Sco OB2 association and searched for near-infrared companions to them with ADONIS and Coronograph. The data acquisition and companions measurement results are described; the mass ratio distribution f(q)=q**(-0.5) is derived using the PMS stars evolution tracks. Target stars J- and K-magnitudes are presented in Table 1; differential photometry and astrometry results for secondary companions and background sources in sky-offset fields are given in Table 2 and 3, respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/464/581
- Title:
- Sco OB2 intermediate-mass stars
- Short Name:
- J/A+A/464/581
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present JHK observations of 22 intermediate-mass stars in Sco OB2, obtained with NACO. This survey was performed to determine the status of (sub)stellar candidate companions of Sco OB2 member stars of spectral type A and late-B. The distinction between companions and background stars is made on the basis of a comparison to isochrones and additional statistical arguments. We include in our sample a subset of 9 targets with multi-color ADONIS observations from Kouwenhoven et al. (2005, Cat. <J/A+A/430/137>). We reanalyse the total sample (i.e. NACO and ADONIS) and conclude that of the 176 secondaries, 25 are physical companions, 55 are candidate companions, and 96 are background stars. Although we are sensitive (and complete) to brown dwarf companions as faint as K=14mag in the semi-major axis range 130-520AU, we detect only one, corresponding to a brown dwarf companion fraction of 0.5% (M>30M_Jupiter_). However, the number of brown dwarfs is consistent with an extrapolation of the (stellar) companion mass distribution into the brown dwarf regime. This indicates that the physical mechanism for the formation of brown dwarf companions around intermediate mass stars is similar to that of stellar companions, and that the embryo ejection mechanism does not need to be invoked in order to explain the small number of brown dwarf companions among intermediate mass stars in Sco OB2.
- ID:
- ivo://CDS.VizieR/J/MNRAS/461/794
- Title:
- Scorpius-Centaurus K-Type Stars
- Short Name:
- J/MNRAS/461/794
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a spectroscopic survey for new K- and M-type members of Scorpius-Centaurus (Sco-Cen), the nearest OB Association (~100-200pc). Using an X-ray, proper motion and color-magnitude selected sample, we obtained spectra for 361 stars, for which we report spectral classifications and Li and Ha equivalent widths. We identified 156 new members of Sco-Cen, and recovered 51 previously published members. We have combined these with previously known members to form a sample of 493 solar-mass (~0.7-1.3M_[sun}_) members of Sco-Cen.We investigated the star-formation history of this sample, and re-assessed the ages of the massive main-sequence turn-off and the G-type members in all three subgroups. We performed a census for circumstellar disks in our sample using WISE infrared data and find a protoplanetary disk fraction for K-type stars of 4.4^+1.6^_-0.9_% for Upper Centaurus-Lupus and Lower Centaurus-Crux at ~16Myr and 9.0^+0.4^_-2.2_% for Upper Scorpius at~10Myr.
- ID:
- ivo://CDS.VizieR/J/ApJ/784/9
- Title:
- SCUBA-2 high-redshift galaxies sample
- Short Name:
- J/ApJ/784/9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the James Clerk Maxwell Telescope's SCUBA-2 camera to image a 400 arcmin^2^ area surrounding the GOODS-N field. The 850 {mu}m rms noise ranges from a value of 0.49 mJy in the central region to 3.5 mJy at the outside edge. From these data, we construct an 850 {mu}m source catalog to 2 mJy containing 49 sources detected above the 4{sigma} level. We use an ultradeep (11.5 {mu}Jy at 5{sigma}) 1.4 GHz image obtained with the Karl G. Jansky Very Large Array together with observations made with the Submillimeter Array to identify counterparts to the submillimeter galaxies. For most cases of multiple radio counterparts, we can identify the correct counterpart from new and existing Submillimeter Array data. We have spectroscopic redshifts for 62% of the radio sources in the 9' radius highest sensitivity region (556/894) and 67% of the radio sources in the GOODS-N region (367/543). We supplement these with a modest number of additional photometric redshifts in the GOODS-N region (30). We measure millimetric redshifts from the radio to submillimeter flux ratios for the unidentified submillimeter sample, assuming an Arp 220 spectral energy distribution. We find a radio-flux-dependent K-z relation for the radio sources, which we use to estimate redshifts for the remaining radio sources. We determine the star formation rates (SFRs) of the submillimeter sources based on their radio powers and their submillimeter fluxes and find that they agree well. The radio data are deep enough to detect star-forming galaxies with SFRs>2000 M_{sun}_/yr to z~6. We find galaxies with SFRs up to ~6000 M_{sun}_/yr over the redshift range z=1.5-6, but we see evidence for a turn-down in the SFR distribution function above 2000 M_{sun}_/yr.
