- ID:
- ivo://CDS.VizieR/J/ApJ/706/762
- Title:
- LAEs at z~4.5 in the LALA Cetus field
- Short Name:
- J/ApJ/706/762
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a large sample of Ly{alpha}-emitting galaxies (LAEs) spectroscopically confirmed at redshift z~4.5, based on Inamori-Magellan Areal Camera and Spectrograph spectroscopic observations of candidate z~4.5 Ly{alpha}-emitting galaxies in the large area Lyman alpha (LALA) narrowband imaging survey Cetus field. We identify 110 of them as z~4.5 Ly{alpha} emitters based on single-line detections with no continuum emission blueward of the line. Six foreground galaxies are identified, either based on multiple lines or blueward continuum emission. The Ly{alpha} confirmation rate varies from <50% to 76% for candidates selected in different narrowband filters at slightly different redshifts. The sample includes many objects with equivalent widths (EWs)>~200{AA}. These large EW candidates are spectroscopically confirmed at the same rate as candidates with more modest EWs.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/738/136
- Title:
- LAEs between 0.19<z<1.25 with GALEX grism
- Short Name:
- J/ApJ/738/136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical spectroscopy of two samples of Galaxy Evolution Explorer grism selected Ly{alpha} emitters (LAEs): one at z=0.195-0.44 and the other at z=0.65-1.25. We have also observed a comparison sample of galaxies in the same redshift intervals with the same UV magnitude distributions but with no detected Ly{alpha}. We use the optical spectroscopy to eliminate active galactic nuclei and to obtain the optical emission-line properties of the samples. We compare the luminosities of the LAEs in the two redshift intervals and show that there is dramatic evolution in the maximum Ly{alpha} luminosity over z=0-1. Focusing on the z=0.195-0.44 samples alone, we show that there are tightly defined relations between all of the galaxy parameters and the rest-frame equivalent width (EW) of H{alpha}. The higher EW(H{alpha}) sources all have lower metallicities, bluer colors, smaller sizes, and less extinction, consistent with their being in the early stages of the galaxy formation process.
- ID:
- ivo://CDS.VizieR/J/ApJ/865/L1
- Title:
- LAEs discovered with ultra-deep MUSE sp. in UDF
- Short Name:
- J/ApJ/865/L1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using an ultra-deep blind survey with the MUSE integral field spectrograph on the European Southern Observatory Very Large Telescope, we obtain spectroscopic redshifts to a depth never before explored: galaxies with observed magnitudes m_AB_>~30-32. Specifically, we detect objects via Ly{alpha} emission at 2.9<z<6.7 without individual continuum counterparts in areas covered by the deepest optical/near-infrared imaging taken by the Hubble Space Telescope, the Hubble Ultra Deep Field. In total, we find 102 such objects in 9 square arcminutes at these redshifts. Detailed stacking analyses confirm the Ly{alpha} emission as well as the 1216 {AA} breaks and faint ultraviolet continua (M_UV_~-15). This makes them the faintest spectroscopically confirmed objects at these redshifts, similar to the sources believed to reionize the universe. A simple model for the expected fraction of detected/undetected Ly{alpha} emitters as a function of luminosity is consistent with these objects being the high-equivalent width tail of the normal Ly{alpha}-emitter population at these redshifts.
- ID:
- ivo://CDS.VizieR/J/other/RAA/15.1392
- Title:
- LAMOST globular clusters in M 31 and M 33
- Short Name:
- J/other/RAA/15.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 908 objects observed with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) in fields in the vicinity of M31 and M33, targeted as globular clusters (GCs) and candidates. The targets include known GCs and candidates selected from the literature, as well as new candidates selected from the Sloan Digital Sky Survey (SDSS). Analysis shows that 356 of them are likely GCs with various confidence levels, while the remaining ones turn out to be background galaxies and quasars, stars and HII regions in M31 or foreground Galactic stars. The 356 likely GCs include 298 bona fide GCs and 26 candidates known in the literature. Three candidates, selected from the Revised Bologna Catalog of M31 GCs and candidates (RBC) and one possible cluster from Johnson et al.(2012, Cat. J/ApJ/752/95), are confirmed to be bona fide clusters. We search for new GCs in the halo of the M31 among the new candidates selected from the SDSS photometry. Based on radial velocities yielded by LAMOST spectra and visual examination of the SDSS images, we find 28 objects, 5 bona fide and 23 likely GCs. Among the five bona fide GCs, three have been recently discovered independently by others, and the remaining 25 are our new identifications, including two bona fide ones. The newly identified objects fall at projected distances ranging from 13 to 265kpc from M31. Of the two newly discovered bona fide GCs, one is located near M33, probably a GC belonging to M33. The other bona fide GC falls on the Giant Stream with a projected distance of 78kpc from M31. Of the 23 newly identified likely GCs, one has a projected distance of about 265kpc from M31 and could be an intergalactic cluster.
- ID:
- ivo://CDS.VizieR/J/other/RAA/15.1424
- Title:
- LAMOST luminous infrared galaxies
- Short Name:
- J/other/RAA/15.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of 64 luminous infrared galaxies, based on new observations of 20 square degrees from the LAMOST Complete Spectroscopic Survey of Pointing Area at the Southern Galactic Cap and the WISE 22um catalog from the AllWISE Data Release. Half of them are classified as late-type spirals and the others are classified as peculiar/compact galaxies. The peculiar/compact galaxies tend to exhibit higher luminosities and lower stellar masses. We also separate AGNs from HII galaxies in a simple way by examining LAMOST spectra. Those cases show that host AGNs are easily distinguished from others in the mid-infrared color-color diagrams.
- ID:
- ivo://CDS.VizieR/J/other/RAA/17.41
- Title:
- LAMOST metal-poor galaxies sample
- Short Name:
- J/other/RAA/17.4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of 48 metal-poor galaxies at z<0.14 selected from 92 510 galaxies in the LAMOST survey. These galaxies are identified by their detection of the auroral emission line [OIII]{lambda}4363 above the 3{sigma} level, which allows a direct measurement of electron temperature and oxygen abundance. The emission line fluxes are corrected for internal dust extinction using the Balmer decrement method. With electron temperature derived from [OIII]{lambda}{lambda}4959,5007/[OIII]{lambda}4363 and electron density from [SII]{lambda}6731/[SII]{lambda}6717, we obtain the oxygen abundances in our sample which range from 12+log(O/H)=7.63(0.09Z_{sun}_) to 8.46 (0.6Z_{sun}_). We find an extremely metal-poor galaxy with 12+log(O/H)=7.63+/-0.01. With multiband photometric data from FUV to NIR and H{alpha} measurements, we also determine the stellar masses and star formation rates, based on the spectral energy distribution fitting and H{alpha} luminosity, respectively. We find that our galaxies have low and intermediate stellar masses with 6.39<=log(M/M_{sun}_)<=9.27, and high star formation rates (SFRs) with -2.18<=log(SFR/M_{sun}_yr^-1^)<=1.95. We also find that the metallicities of our galaxies are consistent with the local T_e_-based mass-metallicity relation, while the scatter is about 0.28dex. Additionally, assuming the coefficient of {alpha}=0.66, we find most of our galaxies follow the local mass-metallicity-SFR relation, but a scatter of about 0.24dex exists, suggesting the mass-metallicity relation is weakly dependent on SFR for those metal-poor galaxies.
- ID:
- ivo://CDS.VizieR/J/other/RAA/15.1438
- Title:
- LAMOST new QSOs in M31 and M33 vicinity
- Short Name:
- J/other/RAA/15.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work, we report new quasars discovered in fields in the vicinity of the Andromeda (M31) and Triangulum (M33) galaxies with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) during the 2013 observational season, the second year of the regular survey. In total, 1330 new quasars are discovered in an area of ~133{deg}^2^ around M31 and M33. With i magnitudes ranging from 14.79 to 20.0 and redshifts from 0.08 to 4.85, the 1330 new quasars represent a significant increase in the number of identified quasars in fields in the vicinity of M31 and M33. Up to now, there have been a total of 1870 quasars discovered by LAMOST in this area. The much enlarged sample of known quasars in this area can potentially be utilized to construct a precise astrometric reference frame for the measurement of minute proper motions of M31, M33 and their associated substructures, which are vital for understanding the formation and evolution of M31, M33 and the Local Group of galaxies. Moreover, in the sample, there are a total of 45, 98 and 225 quasars with i magnitudes brighter than 17.0, 17.5 and 18.0 respectively. In the aforementioned brightness bins, 15, 35 and 84 quasars are reported here for the first time, and 6, 21 and 81 are reported in our previous work. In addition, 0, 1 and 6 are from the Sloan Digital Sky Survey and 24, 41 and 54 are from the NED database. These bright quasars provide an invaluable sample to study the kinematics and chemistry of the interstellar/intergalactic medium of the Local Group.
1928. LAMOST-SDSS galaxy pairs
- ID:
- ivo://CDS.VizieR/J/other/RAA/16.C7
- Title:
- LAMOST-SDSS galaxy pairs
- Short Name:
- J/other/RAA/16.C
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A small fraction (<10%) of the SDSS main galaxy (MG) sample has not been targeted with spectroscopy due to the effect of fiber collisions. These galaxies have been compiled into the input catalog of the LAMOST ExtraGAlactic Surveys and named the complementary galaxy sample. In this paper, we introduce this project and status of the spectroscopies associated with the complementary galaxies in the first two years of the LAMOST spectral survey (till Sep. of 2014). Moreover, we present a sample of 1102 galaxy pairs identified from the LAMOST complementary galaxies and SDSS MGs, which are defined as two members that have a projected distance smaller than 100h_70_^-1^kpc and a recessional velocity difference smaller than 500km/s. Compared with galaxy pairs that are only selected from SDSS, the LAMOST- SDSS pairs have the advantages of not being biased toward large separations and therefore act as a useful supplement in statistical studies of galaxy interaction and galaxy merging.
- ID:
- ivo://CDS.VizieR/J/AJ/155/181
- Title:
- LAMOST/SP_Ace DR1 catalog
- Short Name:
- J/AJ/155/181
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new analysis of the LAMOST DR1 survey spectral database performed with the code SP_Ace, which provides the derived stellar parameters Teff, logg, [Fe/H], and [alpha/H] for 1,097,231 stellar objects. We tested the reliability of our results by comparing them to reference results from high spectral resolution surveys. The expected errors can be summarized as ~120K in Teff, ~0.2 in logg, ~0.15dex in [Fe/H], and ~0.1dex in [alpha/Fe] for spectra with S/N>40, with some differences between dwarf and giant stars. SP_Ace provides error estimations consistent with the discrepancies observed between derived and reference parameters. Some systematic errors are identified and discussed. The resulting catalog is publicly available at the LAMOST and CDS websites.
- ID:
- ivo://CDS.VizieR/J/AJ/152/45
- Title:
- LAMOST survey of star clusters in M31. II.
- Short Name:
- J/AJ/152/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We select from Paper I a sample of 306 massive star clusters observed with the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) in the vicinity fields of M31 and M33, and determine their metallicities, ages, and masses. Metallicities and ages are estimated by fitting the observed integrated spectra with stellar synthesis population (SSP) models with a pixel-to-pixel spectral fitting technique. Ages for most young clusters are also derived by fitting the multi-band photometric measurements with model spectral energy distributions (SEDs). The estimated cluster ages span a wide range, from several million years to the age of the universe. The numbers of clusters younger and older than 1Gyr are, respectively, 46 and 260. With ages and metallicities determined, cluster masses are then estimated by comparing the multi-band photometric measurements with SSP model SEDs. The derived masses range from ~10^3^ to ~10^7^M_{Sun}_, peaking at ~10^4.3^ and ~10^5.7^M_{Sun}_ for young (<1Gyr) and old (>1Gyr) clusters, respectively. Our estimated metallicities, ages, and masses are in good agreement with available literature values. Old clusters richer than [Fe/H]~-0.7dex have a wide range of ages. Those poorer than [Fe/H]~-0.7dex seem to be composed of two groups, as previously found for Galactic globular clusters-one of the oldest ages with all values of metallicity down to ~-2dex and another with metallicity increasing with decreasing age. The old clusters in the inner disk of M31 (0-30kpc) show a clear metallicity gradient measured at -0.038+/-0.023dex/kpc.
