- ID:
- ivo://CDS.VizieR/J/MNRAS/468/2325
- Title:
- YSOs in star-forming region associated to V582 Aur
- Short Name:
- J/MNRAS/468/2325
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have studied the environment of the FU Ori type star V582 Aur. Our aim is to explore the star-forming region associated with this young eruptive star. Using slitless spectroscopy, we searched for H{alpha} emission stars within a field of 11.5 arcmin x 11.5 arcmin, centred on V582 Aur. Based on UKIDSS and Spitzer Space Telescope data, we further selected infrared-excess young stellar object candidates. In all, we identified 68 candidate low-mass young stars, 16 of which exhibited H{alpha} emission in the slitless spectroscopic images. The colour-magnitude diagram of the selected objects, based on the IPHAS data, suggests that they are low-mass pre-main-sequence stars associated with the Aur OB 1 association, located at a distance of 1.3kpc from Sun. The bright-rimmed globules in the local environment of V582 Aur probably belong to the dark cloud LDN 1516. Our results suggest that star formation in these globules might have been triggered by the radiation field of a few hot members of Aur OB 1. The bolometric luminosity of V582 Aur, based on archival photometric data and on the adopted distance, is 150-320L_{sun}_.
« Previous |
1,001 - 1,008 of 1,008
|
Next »
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/822/79
- Title:
- YSOs search in LDN 1340 in optical
- Short Name:
- J/ApJ/822/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have performed an optical spectroscopic and photometric search for young stellar objects associated with the molecular cloud Lynds 1340, and examined the structure of the cloud by constructing an extinction map, based on SDSS data. The new extinction map suggests a shallow, strongly fragmented cloud, having a mass of some 3700M_{sun}_. Longslit spectroscopic observations of the brightest stars over the area of L1340 revealed that the most massive star associated with L1340 is a B4-type, ~5M_{sun}_ star. The new spectroscopic and photometric data of the intermediate-mass members led to a revised distance of 825_-80_^+110^pc, and revealed seven members of the young stellar population with M>~2M_{sun}_. Our search for H{alpha} emission line stars, conducted with the Wide Field Grism Spectrograph 2 on the 2.2m telescope of the University of Hawaii and covering a 30'x40' area, resulted in the detection of 75 candidate low-mass pre-main sequence stars, 58 of which are new. We constructed spectral energy distributions (SEDs) of our target stars, based on SDSS, 2MASS, Spitzer, and WISE photometric data, derived their spectral types, extinctions, and luminosities from BVRIJ fluxes, estimated masses by means of pre-main sequence evolutionary models, and examined the disk properties utilizing the 2-24{mu}m interval of the SED. We measured the equivalent width of the H{alpha} lines and derived accretion rates. The optically selected sample of pre-main sequence stars has a median effective temperature of 3970K, a stellar mass of 0.7M_{sun}_, and an accretion rate of 7.6x10^-9^M_{sun}_/yr.
- ID:
- ivo://CDS.VizieR/J/ApJ/636/1002
- Title:
- Z And UBV photometry and equivalent widths
- Short Name:
- J/ApJ/636/1002
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe observational evidence for a new kind of interacting binary star outburst that involves both an accretion instability and an increase in thermonuclear shell burning on the surface of an accreting white dwarf. We refer to this new type of eruption as a combination nova. In late 2000, the prototypical symbiotic star Z Andromedae brightened by roughly 2mag in the optical. We observed the outburst in the radio with the VLA and MERLIN, in the optical both photometrically and spectroscopically, in the far-ultraviolet with FUSE, and in the X-rays with both Chandra and XMM-Newton.
- ID:
- ivo://CDS.VizieR/J/ApJ/783/119
- Title:
- z~1 Ly{alpha} emitters. I. 135 candidates from GALEX
- Short Name:
- J/ApJ/783/119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We construct a flux-limited sample of 135 candidate z~1 Ly{alpha} emitters (LAEs) from Galaxy Evolution Explorer (GALEX) grism data using a new data cube search method. These LAEs have luminosities comparable to those at high redshifts and lie within a 7Gyr gap present in existing LAE samples. We use archival and newly obtained optical spectra to verify the UV redshifts of these LAEs. We use the combination of the GALEX UV spectra, optical spectra, and X-ray imaging data to estimate the active galactic nucleus (AGN) fraction and its dependence on Ly{alpha} luminosity. We remove the AGNs and compute the luminosity function (LF) from 60 z~1 LAE galaxies. We find that the best-fit LF implies a luminosity density increase by a factor of ~1.5 from z~0.3 to z~1 and ~20 from z~1 to z~2. We find a z~1 volumetric Ly{alpha} escape fraction of 0.7%+/-0.4%.
- ID:
- ivo://CDS.VizieR/J/ApJ/759/133
- Title:
- z=2.4 Ly{alpha} emitters in the 53W002 field
- Short Name:
- J/ApJ/759/133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of our wide-field narrowband imaging of the field around the radio galaxy 53W002 at z=2.390 with Subaru/Suprime-Cam. A custom-made filter, NB413, centered at 4140{AA} with a width of 83{AA} is used to observe the 31'x24' area around the radio galaxy. We detected 204 Ly{alpha} emitters (LAEs) at z=2.4 with a rest-frame equivalent width larger than 25{AA} to the depth of 26 AB mag (in NB413). The entire LAE population in the 53W002 field has an average number density and distributions of equivalent width and size that are similar to those of other fields at z~2. We identify a significant high-density region (53W002F-HDR) that spreads over {approx}5'x4' near 53W002, where the LAE number density is nearly four times as large as the average of the entire field. Using the probability distribution function of density fluctuation, we evaluate the rareness probability of 53W002F-HDR to be 0.9^+2.4^_-0.62_%, which corresponds to a moderately rich structure. No notable environmental dependency at the comoving scale of 10Mpc is found for the distributions of the Ly{alpha} equivalent width and luminosity in the field. We also detected four Ly{alpha} blobs, one of which is newly discovered. They are all located in the rims of high-density regions. The biased location and unique morphologies in Ly{alpha} suggest that galaxy interaction plays a key role in their formation.
- ID:
- ivo://CDS.VizieR/J/ApJ/833/19
- Title:
- 0.02<z<1.4 post-starburst SDSS galaxies
- Short Name:
- J/ApJ/833/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Post-starburst galaxies are in the transitional stage between blue, star-forming galaxies and red, quiescent galaxies and therefore hold important clues for our understanding of galaxy evolution. In this paper, we systematically searched for and identified a large sample of post-starburst galaxies from the spectroscopic data set of the Sloan Digital Sky Survey (SDSS) Data Release 9. In total, we found more than 6000 objects with redshifts between z~0.05 and z~1.3, making this the largest sample of post-starburst galaxies in the literature. We calculated the luminosity function of the post-starburst galaxies using two uniformly selected subsamples: the SDSS main galaxy sample and the Baryon Oscillation Spectroscopic Survey CMASS sample. The luminosity functions are reasonably fit by half-Gaussian functions. The peak magnitudes shift as a function of redshift from M~-23.5 at z~0.8 to M~-20.3 at z~0.1. This is consistent with the downsizing trend, whereby more massive galaxies form earlier than low-mass galaxies. We compared the mass of the post-starburst stellar population found in our sample to the decline of the global star formation rate and found that only a small amount (~1%) of all star formation quenching in the redshift range z=0.2-0.7 results in post-starburst galaxies in the luminosity range our sample is sensitive to. Therefore, luminous post-starburst galaxies are not the place where most of the decline in the star formation rate of the universe is happening.
- ID:
- ivo://CDS.VizieR/J/ApJ/826/114
- Title:
- z~3-6 protoclusters in the CFHTLS deep fields
- Short Name:
- J/ApJ/826/114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of three protoclusters at z~3-4 with spectroscopic confirmation in the Canada-France-Hawaii Telescope Legacy Survey Deep Fields. In these fields, we investigate the large-scale projected sky distribution of z~3-6 Lyman-break galaxies and identify 21 protocluster candidates from regions that are overdense at more than 4{sigma} overdensity significance. Based on cosmological simulations, it is expected that more than 76% of these candidates will evolve into a galaxy cluster of at least a halo mass of 10^14^ M_{sun}_ at z=0. We perform follow-up spectroscopy for eight of the candidates using Subaru/FOCAS, Keck II/DEIMOS, and Gemini-N/GMOS. In total we target 462 dropout candidates and obtain 138 spectroscopic redshifts. We confirm three real protoclusters at z=3-4 with more than five members spectroscopically identified and find one to be an incidental overdense region by mere chance alignment. The other four candidate regions at z~5-6 require more spectroscopic follow-up in order to be conclusive. A z=3.67 protocluster, which has 11 spectroscopically confirmed members, shows a remarkable core-like structure composed of a central small region (<0.5 physical Mpc) and an outskirts region (~1.0 physical Mpc). The Ly{alpha} equivalent widths of members of the protocluster are significantly smaller than those of field galaxies at the same redshift, while there is no difference in the UV luminosity distributions. These results imply that some environmental effects start operating as early as at z~4 along with the growth of the protocluster structure. This study provides an important benchmark for our analysis of protoclusters in the upcoming Subaru/HSC imaging survey and its spectroscopic follow-up with the Subaru/PFS that will detect thousands of protoclusters up to z~6.
- ID:
- ivo://CDS.VizieR/J/A+A/467/565
- Title:
- z=1-3 ULIRGs from the Spitzer SWIRE survey
- Short Name:
- J/A+A/467/565
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-redshift ultra luminous infrared galaxies contribute the bulk of the cosmic IR background and are the best candidates for very massive galaxies in formation at z>1.5. It is necessary to identify the energy source for their huge luminosities, starburst or AGN activity, in order to correctly interpret the role of ULIRGs in galaxy evolution, and compute reliable estimates of their star formation rates, stellar masses, and accretion luminosities.
