- ID:
- ivo://CDS.VizieR/J/ApJS/234/5
- Title:
- LaCoSSPAr in the Southern Galactic Cap. I.
- Short Name:
- J/ApJS/234/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic redshift catalog from the LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap (SGC), which is designed to observe all sources (Galactic and extragalactic) by using repeating observations with a limiting magnitude of r=18.1mag in two 20deg^2^ fields. The project is mainly focusing on the completeness of LAMOST ExtraGAlactic Surveys (LEGAS) in the SGC, the deficiencies of source selection methods, and the basic performance parameters of the LAMOST telescope. In both fields, more than 95% of galaxies have been observed. A post-processing has been applied to the LAMOST 1D spectrum to remove the majority of remaining sky background residuals. More than 10000 spectra have been visually inspected to measure the redshift by using combinations of different emission/absorption features with an uncertainty of {sigma}_z_/(1+z)<0.001. In total, 1528 redshifts (623 absorption and 905 emission line galaxies) in Field A and 1570 redshifts (569 absorption and 1001 emission line galaxies) in Field B have been measured. The results show that it is possible to derive redshift from low S/N galaxies with our post-processing and visual inspection. Our analysis also indicates that up to one-fourth of the input targets for a typical extragalactic spectroscopic survey might be unreliable. The multi-wavelength data analysis shows that the majority of mid-infrared-detected absorption (91.3%) and emission line galaxies (93.3%) can be well separated by an empirical criterion of W2-W3=2.4. Meanwhile, a fainter sequence paralleled to the main population of galaxies has been witnessed both in Mr/W2-W3 and M*/W2-W3 diagrams, which could be the population of luminous dwarf galaxies but contaminated by the edge-on/highly inclined galaxies (~30%).
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Search Results
1312. 10 Lac UV spectral atlas
- ID:
- ivo://CDS.VizieR/J/AJ/116/941
- Title:
- 10 Lac UV spectral atlas
- Short Name:
- J/AJ/116/941
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of the narrow-lined O-type star 10 Lacertae taken with the Goddard High Resolution Spectrograph in 1992 November are presented. The spectra cover the wavelength range 1181-1777{AA} with a resolution of 15km/s and signal-to-noise ratio greater than 100:1. Absorption lines arising in the interstellar medium, the photosphere, and the stellar wind are identified and discussed.
- ID:
- ivo://CDS.VizieR/J/MNRAS/468/1123
- Title:
- LAE among star-forming galaxies at z=2.5
- Short Name:
- J/MNRAS/468/1123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We conducted a deep narrow-band imaging survey with the Subaru Prime Focus Camera on the Subaru Telescope and constructed a sample of Ly{alpha} emitters (LAEs) at z=2.53 in the UDS-CANDELS field, where a sample of H{alpha} emitters (HAEs) at the same redshift is already obtained from our previous narrow-band observation at near-infrared. The deep narrow-band and multibroad-band data allow us to find LAEs of stellar masses and star formation rates (SFRs) down to >=10^8^M_{sun}_ and >=0.2 M_{sun}_/yr, respectively. We show that the LAEs are located along the same mass-SFR sequence traced by normal star-forming galaxies such as HAEs, but towards a significantly lower mass regime. Likewise, LAEs seem to share the same mass-size relation with typical star-forming galaxies, except for the massive LAEs that tend to show significantly compact sizes. We identify a vigorous mass growth in the central part of LAEs: the stellar mass density in the central region of LAEs increases as their total galaxy mass grows. On the other hand, we see no Ly{alpha} line in emission for most of the HAEs. Rather, we find that the Ly{alpha} feature is either absent or in absorption (Ly{alpha} absorbers, LAAs), and its absorption strength may increase with reddening of the UV continuum slope. We demonstrate that a deep Ly{alpha} narrow-band imaging like this study is able to search for not only LAEs but also LAAs in a certain redshift slice. This work suggests that LAEs trace normal star-forming galaxies in the low-mas
- 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.
- 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/ApJ/818/30
- Title:
- Lag measurements for 15 z<0.8 QSOs from the SDSS-RM
- Short Name:
- J/ApJ/818/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Reverberation mapping (RM) measurements of broad-line region (BLR) lags in z>0.3 quasars are important for directly measuring black hole masses in these distant objects, but so far there have been limited attempts and success given the practical difficulties of RM in this regime. Here we report preliminary results of 15 BLR lag measurements from the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project, a dedicated RM program with multi-object spectroscopy designed for RM over a wide redshift range. The lags are based on the 2014 spectroscopic light curves alone (32 epochs over six months) and focus on the H{beta} and Mg II broad lines in the 100 lowest-redshift (z<0.8) quasars included in SDSS-RM; they represent a small subset of the lags that SDSS-RM (including 849 quasars to z~4.5) is expected to deliver. The reported preliminary lag measurements are for intermediate-luminosity quasars at 0.3<~z<0.8, including nine H{beta} lags and six Mg II lags, for the first time extending RM results to this redshift-luminosity regime and providing direct quasar black hole mass estimates over approximately half of cosmic time. The Mg II lags also increase the number of known Mg II lags by several fold and start to explore the utility of Mg II for RM at high redshift. The location of these new lags at higher redshifts on the observed BLR size-luminosity relationship is statistically consistent with previous H{beta} results at z<0.3. However, an independent constraint on the relationship slope at z>0.3 is not yet possible owing to the limitations in our current sample. Our results demonstrate the general feasibility and potential of multi-object RM for z>0.3 quasars.
1318. LAMOST DR5 catalogs
- ID:
- ivo://CDS.VizieR/V/164
- Title:
- LAMOST DR5 catalogs
- Short Name:
- V/164
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We totally published 9,026,365 targets in this table, including 8,183,160 stars, 152,863 galaxies, 52,453 quasars, and 637,889 unknown objects. In addition, there are 5,808,985 objects with g band S/Ns larger than 10, 7,701,235 objects with i band S/Ns larger than 10, and 5,734,239 objects with g band S/Ns larger than 10 and i band S/Ns larger than 10. On the website http://dr5.lamost.org/catalogue, we provide two format LAMOST general catalogs, which include a FITS table and a CSV table, and the two catalog files have the same contents.
1319. LAMOST DR4 catalogs
- ID:
- ivo://CDS.VizieR/V/153
- Title:
- LAMOST DR4 catalogs
- Short Name:
- V/153
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) is a Chinese national scientific research facility operated by the National Astronomical Observatories, Chinese Academy of Sciences. It is a special reflecting Schmidt telescope with 4000 fibers in a field of view of 20 deg22in the sky. Until July 2016, LAMOST has completed its pilot survey which was launched in October 2011 and ended in June 2012, and the first four years of regular survey which was initiated on September 2012. After this five-year-survey, we totally obtain 7,617,035 spectra, which consist of stars, galaxies, quasars and other unknown objects. Now, the fourth data release (DR4) has published online (http://dr4.lamost.org/), and released data products include 1. Spectra. - In general, there are 7,617,035 flux- and wavelength-calibrated, sky-subtracted spectra in DR4, including 6,943,865 stars, 117,254 galaxies, 36,575 quasars, and 519,341 unknown objects, and these spectra cover the wavelength range of 3690-9100 angstrom with a resolution of 1800 at the 5500 angstrom. 2. Spectroscopic Parameters Catalogs. - In this data release, six spectroscopic parameters catalogs are also published, they are the LAMOST general catalog, the A, F, G and K type star catalog, the A type star catalog, the M dwarf catalog, the observed plate information catalog, and the input catalog respectively. For the first four catalogs, they all include 36 columns of basic spectroscopic information, for example, right ascension, declination, signal to noise ratio, magnitude, classification and redshift. Also, the A type star catalog publish line indices of six spectral lines and four balmer line widths at 20% below the local continua, the A, F, G and K type star catalog provides effective temperature, surface gravity, and metallicity, and the M dwarf catalog releases the equivalent width of Halpha line, ten line indices, one metallicity sensitive parameter and a flag that indicates whether or not exist magnetic activity. For the observed plate information catalog, it mainly contains nine basic plate information for all published plates. At last, the input catalog includes 24 basic fields mentioned above, and three new fields which are not included in the above catalogs.
1320. LAMOST DR2 catalogs
- ID:
- ivo://CDS.VizieR/V/149
- Title:
- LAMOST DR2 catalogs
- Short Name:
- V/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Large sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) general survey is a spectroscopic survey that will eventually cover approximately half of the celestial sphere and collect 10 million spectra of stars, galaxies and QSOs.
