- ID:
- ivo://CDS.VizieR/J/MNRAS/462/1444
- Title:
- MHO catalogue for Cassiopeia and Auriga
- Short Name:
- J/MNRAS/462/1444
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of 35.5deg^2^ of images in the 1-0 S(1) line of H_2_ from the UK Widefield Infrared Survey for H_2_ (UWISH2) towards Cassiopeia and Auriga. We have identified 98 Molecular Hydrogen emission-line Objects (MHOs) driven by Young Stellar Objects, 60 per cent of which are bipolar outflows and all are new discoveries. We estimate that the UWISH2-extended emission object catalogue contains fewer than 2 per cent false positives and is complete at the 95 per cent level for jets and outflows brighter than the UWISH2 detection limit. We identified reliable driving source candidates for three quarters of the detected outflows, 40 per cent of which are associated with groups and clusters of stars. The driving source candidates are 20 per cent protostars, the remainder are Classical T-Tauri Stars. We also identified 15 new star cluster candidates near MHOs in the survey area. We find that the typical outflow identified in the sample has the following characteristics: the position angles are randomly orientated; bipolar outflows are straight within a few degrees; the two lobes are slightly asymmetrical in length and brightness; the length and brightness of the lobes are not correlated; typical time gaps between major ejections of material are 1-3 kyr, hence FU-Ori or EX-Ori eruptions are most likely not the cause of these, but we suggest MNors as a possible source. Furthermore, we find that outflow lobe length distributions are statistically different from the widely used total length distributions. There are a larger than expected number of bright outflows indicating that the flux distribution does not follow a power law.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/421/3257
- Title:
- MHO catalogue for Serpens and Aquila
- Short Name:
- J/MNRAS/421/3257
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Jets and outflows from young stellar objects (YSOs) are important signposts of currently ongoing star formation. In order to study these objects, we are conducting an unbiased survey along the Galactic plane in the 1-0 S(1) emission line of molecular hydrogen at 2.122 um using the United Kingdom Infrared Telescope. In this paper, we are focusing on a 33-deg^2^-sized region in Serpens and Aquila (18{deg}<l<30{deg}; -1.5{deg}<b<+1.5{deg}). We trace 131 jets and outflows from YSOs, which results in a 15-fold increase in the total number of known molecular hydrogen outflows. Compared to this, the total integrated 1-0 S(1) flux of all objects just about doubles, since the known objects occupy the bright end of the flux distribution. Our completeness limit is 3x10^-18^W/m^2^ with 70 per cent of the objects having fluxes of less than 10^-17^W/m^2^.
- ID:
- ivo://CDS.VizieR/J/ApJ/844/38
- Title:
- MHOs toward 22 regions with H2 fluxes
- Short Name:
- J/ApJ/844/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a narrow-band near-infrared imaging survey for Molecular Hydrogen emission-line Objects (MHOs) toward 26 regions containing high-mass protostellar candidates and massive molecular outflows. We have detected a total of 236 MHOs, 156 of which are new detections, in 22 out of the 26 regions. We use H_2_2.12{mu}m/H_2_2.25{mu}m flux ratios, together with morphology, to separate the signatures of fluorescence associated with photo- dissociation regions (PDRs) from shocks associated with outflows in order to identify the MHOs. PDRs have typical low flux ratios of ~1.5-3, while the vast majority of MHOs display flux ratios typical of C-type shocks (~6-20). A few MHOs exhibit flux ratios consistent with expected values for J-type shocks (~3-4), but these are located in regions that may be contaminated with fluorescent emission. Some previously reported MHOs have low flux ratios, and are likely parts of PDRs rather than shocks indicative of outflows. We identify a total of 36 outflows across the 22 target regions where MHOs were detected. In over half these regions, MHO arrangements and fluorescent structures trace features present in CO outflow maps, suggesting that the CO emission traces a combination of dynamical effects, which may include gas entrained in expanding PDRs as well as bipolar outflows. Where possible, we link MHO complexes to distinct outflows and identify candidate driving sources.
- ID:
- ivo://CDS.VizieR/J/ApJS/159/242
- Title:
- 325MHz radio survey in M31. II.
- Short Name:
- J/ApJS/159/242
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have previously presented the results of a 325MHz radio survey of M31 (Cat. <J/ApJS/155/89>, conducted with the A configuration of the Very Large Array. In this survey, a total of 405 radio sources between <~6" and 170" in extent were mapped with a resolution of 6" and a sensitivity of ~0.6mJy/beam. Here we compare the resultant source list and image with other radio, IR, optical, and X-ray observations and catalogs of the region.
- ID:
- ivo://CDS.VizieR/J/ApJS/244/29
- Title:
- Microlensing events toward the Galactic bulge
- Short Name:
- J/ApJS/244/29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The number and properties of observed gravitational microlensing events depend on the distribution and kinematics of stars and other compact objects along the line of sight. In particular, precise measurements of the microlensing optical depth and event rate toward the Galactic bulge enable strict tests of competing models of the Milky Way. Previous estimates, based on samples of up to a few hundred events, gave larger values than expected from the Galactic models and were difficult to reconcile with other constraints on the Galactic structure. Here we used long-term photometric observations of the Galactic bulge by the Optical Gravitational Lensing Experiment (OGLE) to select a homogeneous sample of 8000 gravitational microlensing events. We created the largest and most accurate microlensing optical depth and event rate maps of the Galactic bulge. The new maps ease the tension between the previous measurements and Galactic models. They are consistent with some earlier calculations based on bright stars and are systematically ~30% smaller than the other estimates based on "all-source" samples of microlensing events. The difference is caused by the careful estimation of the source star population. The new maps agree well with predictions based on the Besancon model of the Galaxy. Apart from testing the Milky Way models, our maps may have numerous other applications, such as the measurement of the initial mass function or constraining the dark matter content in the Milky Way center. The new maps will also inform the planning of future space-based microlensing experiments by revising the expected number of events.
- ID:
- ivo://CDS.VizieR/II/56
- Title:
- 100-Micron Survey of the Galactic Plane
- Short Name:
- II/56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog represents a survey of a portion of the galactic plane at a wavelength of 100 micrometers with a balloon-borne, stabilized, 12-inch infrared telescope having a sensitivity of 10(-22) W/m2/Hz. The survey covers 750 square degrees of the sky, including most of the galactic plane between galactic longitudes of 335 and 88 degrees, plus a number of other selected areas of interest. Seventy-two sources have been detected, 60 of which are identified with continuum radio sources, bright nebulae, dark nebulae, and infrared stars. The catalog includes right ascension and declination (B1950.0), galactic coordinates, 100-micrometer peak flux densities, sizes of sources, and identifications.
- ID:
- ivo://CDS.VizieR/J/ApJ/697/506
- Title:
- Mid-infrared galaxy luminosity function from AGN
- Short Name:
- J/ApJ/697/506
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present galaxy luminosity functions at 3.6, 4.5, 5.8, and 8.0um measured by combining photometry from the IRAC Shallow Survey with redshifts from the AGN and Galaxy Evolution Survey (AGES) of the NOAO Deep Wide-Field Survey Bootes field. The well defined IRAC samples contain 3800-5800 galaxies for the 3.6-8.0um bands with spectroscopic redshifts and z<0.6. We obtained relatively complete luminosity functions in the local redshift bin of z<0.2 for all four IRAC channels that are well fitted by Schechter functions.
- ID:
- ivo://CDS.VizieR/J/AJ/127/3075
- Title:
- Mid-infrared population of ELAIS-S1 sample
- Short Name:
- J/AJ/127/3075
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multiwavelength catalog (15{mu}m, R-band, K-band, and 1.4GHz flux) plus spectroscopic identifications for 406 15{mu}m sources detected in the European Large Area ISO Survey (ELAIS) region S1, over the flux density range 0.5<S15{mu}m<150mJy. Three hundred thirty-two (~82%) sources are optically identified down to R~23.0. Spectra or bona fide stellar identifications are obtained for 290 objects (~88% of the optically identified sources). The areal coverage, mid-infrared (MIR) and optical completeness of the sample are discussed in order to allow statistical and evolutionary analyses.
- ID:
- ivo://CDS.VizieR/J/MNRAS/441/715
- Title:
- Mid-infrared study of RR Lyrae stars
- Short Name:
- J/MNRAS/441/715
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a group of 3740 previously identified RR Lyrae variables well observed with the Wide-field Infrared Survey Explorer (WISE). We explore how the shape of the generic RR Lyrae mid-infrared light curve varies over period-space, comparing light curves in mid-infrared and optical bands. We find that optical light curves exhibit high amplitudes and a large spectrum of light-curve shapes, while mid-infrared light curves have low amplitudes and uniform light-curve shapes. From the period-space analysis, we hope to improve the classification methods of RR Lyrae variables and enable reliable discovery of these pulsators in the WISE catalogue and future mid-infrared surveys such as the James Webb Space Telescope. We provide mid-infrared templates for typical RR Lyrae stars and demonstrate how these templates can be applied to improve estimates of mid-infrared RR Lyrae mean magnitude, which is used for distance measurement. This method of template fitting is particularly beneficial for improving observational efficiency. For example, using light curves with observational noise of 0.05mag, we obtain the same level of accuracy in mean magnitude estimates for light curves randomly sampled at 12 data points with template fitting as with light curves randomly sampled at 20 data points with harmonic modelling.
- ID:
- ivo://CDS.VizieR/J/ApJ/636/932
- Title:
- Mid-infrared survey of T Tauri stars
- Short Name:
- J/ApJ/636/932
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a high spatial resolution, 10-20{mu}m survey of 65 T Tauri binary stars in Taurus, Ophiuchus, and Corona Australis using the Keck 10m telescopes. Designed to probe the inner ~1AU region of the circumstellar disks around the individual stellar components in these binary systems, this study increases the number of binaries with spatially resolved measurements at 10{mu}m by a factor of ~5.
