- ID:
- ivo://CDS.VizieR/J/ApJ/767/94
- Title:
- 1.1-1.9GHz SETI survey of KOIs. I.
- Short Name:
- J/ApJ/767/94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a targeted search for narrow-band (<5Hz) drifting sinusoidal radio emission from 86 stars in the Kepler field hosting confirmed or candidate exoplanets. Radio emission less than 5Hz in spectral extent is currently known to only arise from artificial sources. The stars searched were chosen based on the properties of their putative exoplanets, including stars hosting candidates with 380K>T_eq_>230K, stars with five or more detected candidates or stars with a super-Earth (R_p_<3R_{earth}_) in a >50 day orbit. Baseband voltage data across the entire band between 1.1 and 1.9GHz were recorded at the Robert C. Byrd Green Bank Telescope between 2011 February and April and subsequently searched offline. No signals of extraterrestrial origin were found. We estimate that fewer than ~1% of transiting exoplanet systems host technological civilizations that are radio loud in narrow-band emission between 1 and 2GHz at an equivalent isotropically radiated power (EIRP) of ~1.5x10^21^erg/s, approximately eight times the peak EIRP of the Arecibo Planetary Radar, and we limit the number of 1-2GHz narrow-band-radio-loud Kardashev type II civilizations in the Milky Way to be <10^-6^/M_{sun}_. Here we describe our observations, data reduction procedures and results.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/640/982
- Title:
- 43GHz SiO maser features around VX Sgr
- Short Name:
- J/ApJ/640/982
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report Very Long Baseline Array (VLBA) observations of 43GHz v=1, J=1-0 SiO masers in the circumstellar envelope of the M-type semiregular variable star VX Sgr at three epochs during 1999 April-May. These high-resolution VLBA images reveal a persistent ringlike distribution of SiO masers with a projected radius of ~3 stellar radii. The typical angular size of 0.5mas for individual maser features was estimated from two-point correlation function analysis of maser spots.
- ID:
- ivo://CDS.VizieR/J/A+A/418/103
- Title:
- 86GHz SiO maser survey in the Inner Galaxy
- Short Name:
- J/A+A/418/103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a compilation and study of DENIS, 2MASS, ISOGAL, MSX and IRAS 1-25 microns photometry for a sample of 441 late-type stars in the inner Galaxy, which we previously searched for 86GHz SiO maser emission (Messineo et al., 2002, Cat. <J/A+A/393/115>). The comparison of the DENIS and 2MASS J and Ks magnitudes shows that most of the SiO targets are indeed variable stars. The MSX colours and the IRAS [12]-[25] colour of our SiO targets are consistent with those of Mira type stars with dust silicate feature at 9.7 microns feature in emission, indicating only a moderate mass-loss rate.
- ID:
- ivo://CDS.VizieR/J/A+A/393/115
- Title:
- 86GHz SiO maser survey of late-type stars
- Short Name:
- J/A+A/393/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 86GHz (v=1, J=2-1) SiO maser line observations with the IRAM 30-m telescope of a sample of 444 late-type stars in the Inner Galaxy (-4{deg}<l<+30{deg}). These stars were selected on basis of their infrared magnitudes and colours from the ISOGAL and MSX catalogues. SiO maser emission was detected in 271 sources, and their line-of-sight velocities indicate that the stars are located in the Inner Galaxy. These new detections double the number of line-of-sight velocities available from previous SiO and OH maser observations in the area covered by our survey and are, together with other samples of e.g. OH/IR stars, useful for kinematic studies of the central parts of the Galaxy.
- ID:
- ivo://CDS.VizieR/J/A+A/435/575
- Title:
- 86GHz SiO maser survey of late-type stars. III
- Short Name:
- J/A+A/435/575
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have determined extinction corrections for a sample of 441 late-type stars in the inner Galaxy, which we previously searched for SiO maser emission, using the 2MASS near-infrared photometry of the surrounding stars. From this, the near-infrared extinction law is found to be approximated by a power law A_lambda_{prop.to}lambda^-1.9+/-0.1^. Near- and mid-infrared colour-colour properties of known Mira stars are reviewed. From the distribution of the dereddened infrared colours of the SiO target stars we infer mass-loss rates between 10^-7^ and 10^-5^M_{sun}_/yr.
- ID:
- ivo://CDS.VizieR/J/A+A/619/A35
- Title:
- 86GHz SiO maser survey of late-type stars. IV
- Short Name:
- J/A+A/619/A35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an 86GHz SiO (v=1, J=2->1) maser search towards late-type stars located within |b|<0.5{deg} and 20{deg}<l<50{deg}. This search is an extension at longer longitudes of the work by Messineo et al. (2002, Cat. J/A+A/393/115). We selected 135 stars from the MSX catalog using color and flux criteria and detected 92 (86 new detections). The detection rate is 68%, the same as in our previous study. The last few decades have seen the publication of several catalogues of point sources detected in infrared surveys (MSX, 2MASS, DENIS, ISOGAL, WISE, GLIMPSE, AKARI, and MIPSGAL). We searched each catalogue for data on the 444 targets of our earlier survey and for the 135 in the survey reported here. We confirm that, as anticipated, most of our targets have colors typical of oxygen-rich AGB stars. Only one target star may have left the AGB already. Ten stars have colors typical of carbon-rich stars, meaning a contamination of our sample with carbon stars of <=1.7%.
- ID:
- ivo://CDS.VizieR/J/ApJ/716/521
- Title:
- 31GHz sky survey with the SZA
- Short Name:
- J/ApJ/716/521
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first sample of 31GHz selected sources to flux levels of 1mJy. From late 2005 to mid-2007, the Sunyaev-Zel'dovich Array observed 7.7deg^2^ of the sky at 31GHz to a median rms of 0.18mJy/beam. We identify 209 sources at greater than 5{sigma} significance in the 31GHz maps, ranging in flux from 0.7mJy to ~200mJy. Archival NVSS data at 1.4GHz and observations at 5GHz with the Very Large Array are used to characterize the sources. We determine the maximum-likelihood integrated source count to be N(>S)=(27.2+/-2.5)deg^-2^x(S_mJy_)^-1.18+/-0.12^ over the flux range 0.7-15mJy. This result is significantly higher than predictions based on 1.4GHz selected samples, a discrepancy which can be explained by a small shift in the spectral index distribution for faint 1.4GHz sources. From comparison with previous measurements of sources within the central arcminute of massive clusters, we derive an overdensity of 6.8+/-4.4, relative to field sources.
- ID:
- ivo://CDS.VizieR/J/ApJ/845/44
- Title:
- 340GHz SMA obs. of 50 nearby protoplanetary disks
- Short Name:
- J/ApJ/845/44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a survey at subarcsecond resolution of the 340GHz dust continuum emission from 50 nearby protoplanetary disks, based on new and archival observations with the Submillimeter Array. The observed visibility data were modeled with a simple prescription for the radial surface brightness profile. The results were used to extract intuitive, empirical estimates of the emission "size" for each disk, R_eff_, defined as the radius that encircles a fixed fraction of the total continuum luminosity, L_mm_. We find a significant correlation between the sizes and luminosities, such that R_eff_{propto}L_mm_^0.5^, providing a confirmation and quantitative characterization of a putative trend that was noted previously. This correlation suggests that these disks have roughly the same average surface brightness interior to their given effective radius, ~0.2Jy/arcsec^2^ (or 8K in brightness temperature). The same trend remains, but the 0.2dex of dispersion perpendicular to this relation essentially disappears, when we account for the irradiation environment of each disk with a crude approximation of the dust temperatures based on the stellar host luminosities. We consider two (not mutually exclusive) explanations for the origin of this size-luminosity relationship. Simple models of the growth and migration of disk solids can account for the observed trend for a reasonable range of initial conditions, but only on timescales that are much shorter than the nominal ages present in the sample. An alternative scenario invokes optically thick emission concentrated on unresolved scales, with filling factors of a few tens of percent, which is perhaps a manifestation of localized particle traps.
7269. 1.4 GHz source survey
- ID:
- ivo://CDS.VizieR/J/AJ/99/1071
- Title:
- 1.4 GHz source survey
- Short Name:
- J/AJ/99/1071
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on 1.4GHz continuum observations for 56 contiguous VLA fields, using the D configuration, in a region devoid of nearby, rich galaxy clusters (at z<0.4). 354 continuum sources are tabulated, with fluxes down to about 1.5mJy, in an area of about 12degres^+2^. Only about seven of the 354 radio sources are associated with known rich galaxy clusters at z>0.4 (tabulated by Gunn, Hoessel, and Oke, 1986ApJ...306...30G). We compare source positions with those from an optical catalog (generated from a POSS plate with the use of the Minnesota Automated Plate Scanner) and find mild correlations on angular scales of order 1arcmin. This suggests some association of radio sources with galaxy groups (sizes of order 200 kpc) at redshifts of order z~0.1, even though there are no rich galaxy clusters in this redshift range.
- ID:
- ivo://CDS.VizieR/J/A+A/325/1163
- Title:
- 330-360GHz spectral lines of G 34.3+0.15. II.
- Short Name:
- J/A+A/325/1163
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Tables 5 and 6 present calculated column densities (in units of molecules per cm^2^) of various species in the ultracompact core (UCC), the compact core (CC) and the halo, together with the total column density and the observed column density where available. Table 5 gives column densities at a time of 3x10^3yrs in the UCC and CC components and at 10^5yrs in the halo. Table 6 gives column densities at a time of 10^4yrs in the UCC and CC components and 10^5yrs in the halo.