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3391. KV Vel and TW Crv JHK light curves
ID:
ivo://CDS.VizieR/J/A+A/526/A150
Title:
KV Vel and TW Crv JHK light curves
Short Name:
J/A+A/526/A150
Date:
21 Oct 2021
Publisher:
CDS
Description:
From a number of known post common envelopes binaries (PCEB) only a handful have yet been observed at near-infrared (NIR) wavelengths, and even fewer have modeled NIR light curves. At shorter wavelengths one has access to the cooler and larger components of these systems and has a chance to detect emission from its faint and heavily irradiated atmospheres. By modeling NIR light curves of PCEBs, we intend to constrain their system parameters and study the properties of the system components.
3392. KX redshift survey
ID:
ivo://CDS.VizieR/J/MNRAS/328/150
Title:
KX redshift survey
Short Name:
J/MNRAS/328/150
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper we present preliminary spectroscopic results from a small-area faint K-excess (KX) survey, and compare KX selection against UVX selection. The aim of the KX method is to produce complete samples of QSOs that are flux-limited in the K band, in order to minimize any selection bias in samples of QSOs from the effects of reddening and extinction. Using the photometric catalogue of the ESO Imaging Survey Chandra Deep Field South (48arcmin^2^) we have identified compact objects with J-K colours redder than the stellar sequence that are brighter than K=19.5. We have obtained spectra of 33 candidates, using the LDSS++ spectrograph on the Anglo-Australian Telescope (AAT). Amongst the 11 bluer candidates, with V-J<3, three are confirmed as QSOs. Identification of the 22 redder candidates with V-J>=3 is substantially incomplete, but so far no reddened QSOs have been found. Near-infrared spectroscopy will be more effective in identifying some of these targets. Only two UVX (U-B<-0.2) sources brighter than K=19.5 are found that are not also KX selected. These are both identified as galactic stars. Thus KX selection appears to select all UVX QSOs. The surface density of QSOs in the blue subsample (V-J<3) at K<=19.5 is 325^+136^_-177_{deg}^-2^. Because identification of the red subsample (V-J>=3) is substantially incomplete, the 2{sigma} upper limit on the density of reddened QSOs is large, <1150{deg}^-2^. As anticipated, at these faint magnitudes the KX sample includes several compact galaxies. Of the 14 with measured redshifts, there are roughly equal numbers of early- and late-type objects. Nearly all the early-type galaxies are found in a single structure at z=0.66.
3393. Kyiv Meridian Axial Circle Catalogue, KMAC1
ID:
ivo://CDS.VizieR/J/A+A/438/377
Title:
Kyiv Meridian Axial Circle Catalogue, KMAC1
Short Name:
J/A+A/438/377
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results of astrometric observations of faint V<17mag stars in sky strip areas with ICRF objects obtained with the Kyiv meridian axial circle (D=180mm) equipped with a 1040x1160 CCD micrometer. Observations were carried out in a declination zone of 0+30 degrees. The work resulted in a compilation of a catalogue KMAC1 that presents an extension of the ICRF to faint stars in optical domain. The catalogue was obtained in the two versions: with reduction to the space catalogue Tycho2, <I/259>, (the version KMAC1-T, 159 ICRF fields, 104794 stars) and with reduction to the modern CCD catalogues CMC13 and UCAC2 (<I/289>) which are given also in the ICRF system (the version KMAC1-CU, 192 ICRF fields, 115032 stars). Due to a large number of CMC13 and UCAC2 stars used as reference, the version KMAC1-CU is of slightly better accuracy, though it may inherit local systematic errors of reference catalogues.
3394. KZ Hya times of maximum light
ID:
ivo://CDS.VizieR/J/AJ/135/1958
Title:
KZ Hya times of maximum light
Short Name:
J/AJ/135/1958
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present 109 new times of maximum light of the SX Phoenicis (SX Phe) star KZ Hydrae (KZ Hya) based mainly on our extensive photometric observations for two decades, leading to determination of a general ephemeris combined with the data in the literature.
3395. LABOCA ECDFS Submillimeter Survey (LESS)
ID:
ivo://CDS.VizieR/J/ApJ/707/1201
Title:
LABOCA ECDFS Submillimeter Survey (LESS)
Short Name:
J/ApJ/707/1201
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a sensitive 870um survey of the Extended Chandra Deep Field South (ECDFS) combining 310hr of observing time with the Large Apex BOlometer Camera (LABOCA) on the APEX telescope. The LABOCA ECDFS Submillimetre Survey (LESS) covers the full 30'x30' field size of the ECDFS and has a uniform noise level of {sigma}_870um_~1.2mJy/beam. LESS is thus the largest contiguous deep submillimeter survey undertaken to date. The noise properties of our map show clear evidence that we are beginning to be affected by confusion noise. We present a catalog of 126 submillimeter galaxies (SMGs) detected with a significance level above 3.7{sigma}, at which level we expect five false detections given our map area of 1260arcmin^2^.
3396. LaCoSSPAr in the Southern Galactic Cap. I.
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%).
3397. LAE cand. at z~5.7 in the field of QSO J0148+0600
ID:
ivo://CDS.VizieR/J/ApJ/863/92
Title:
LAE cand. at z~5.7 in the field of QSO J0148+0600
Short Name:
J/ApJ/863/92
Date:
21 Oct 2021
Publisher:
CDS
Description:
The observed scatter in intergalactic Ly{alpha} opacity at z<~6 requires large-scale fluctuations in the neutral fraction of the intergalactic medium (IGM) after the expected end of reionization. Post-reionization models that explain this scatter invoke fluctuations in either the ionizing ultraviolet background (UVB) or IGM temperature. These models make very different predictions, however, for the relationship between Ly{alpha} opacity and local density. Here, we test these models using Ly{alpha}-emitting galaxies (LAEs) to trace the density field surrounding the longest and most opaque known Ly{alpha} trough at z<6. Using deep Subaru Hyper Suprime-Cam narrowband imaging, we find a highly significant deficit of z~5.7 LAEs within 20h^-1^Mpc of the trough. The results are consistent with a model in which the scatter in Ly{alpha} opacity near z~6 is driven by large-scale UVB fluctuations, and disfavor a scenario in which the scatter is primarily driven by variations in IGM temperature. UVB fluctuations at this epoch present a boundary condition for reionization models, and may help shed light on the nature of the ionizing sources.
3398. Lag-luminosity relationship in AGN
ID:
ivo://CDS.VizieR/J/ApJ/622/129
Title:
Lag-luminosity relationship in AGN
Short Name:
J/ApJ/622/129
Date:
21 Oct 2021
Publisher:
CDS
Description:
We determine interband lags between variations in the B band and variations in the V, R, and I bands for 14 active galactic nuclei observed at the Crimean Astrophysical Observatory. The computed lags range from tenths of a day to several days, and it is positive (that is, V, R, and I bands lag behind the B band) in most cases, except for a few cases for the V filter.
3399. Lagoon Nebula M8 T tauri accretion rates
ID:
ivo://CDS.VizieR/J/MNRAS/453/1026
Title:
Lagoon Nebula M8 T tauri accretion rates
Short Name:
J/MNRAS/453/1026
Date:
03 Nov 2021
Publisher:
CDS
Description:
We estimate the accretion rates of 235 Classical T Tauri star (CTTS) candidates in the Lagoon Nebula using ugri H{alpha} photometry from the VST Photometric H{alpha} survey+. Our sample consists of stars displaying H{alpha} excess, the intensity of which is used to derive accretion rates. For a subset of 87 stars, the intensity of the u-band excess is also used to estimate accretion rates. We find the mean variation in accretion rates measured using H{alpha} and u-band intensities to be ~0.17dex, agreeing with previous estimates (0.04-0.4dex) but for a much larger sample. The spatial distribution of CTTS align with the location of protostars and molecular gas suggesting that they retain an imprint of the natal gas fragmentation process. Strong accretors are concentrated spatially, while weak accretors are more distributed. Our results do not support the sequential star-forming processes suggested in the literature.
3400. Lagoon Nebula stars. I. Rotation periods
ID:
ivo://CDS.VizieR/J/ApJ/747/51
Title:
Lagoon Nebula stars. I. Rotation periods
Short Name:
J/ApJ/747/51
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have conducted a long-term, wide-field, high-cadence photometric monitoring survey of ~50000 stars in the Lagoon Nebula H II region. This first paper presents rotation periods for 290 low-mass stars in NGC 6530, the young cluster illuminating the nebula, and for which we assemble a catalog of infrared and spectroscopic disk indicators, estimated masses and ages, and X-ray luminosities. The distribution of rotation periods we measure is broadly uniform for 0.5days<P<10days; the short-period cutoff corresponds to breakup. We observe no obvious bimodality in the period distribution, but we do find that stars with disk signatures rotate more slowly on average. The stars' X-ray luminosities are roughly flat with rotation period, at the saturation level (log L_X_/L_bol_{approx} -3.3). However, we find a significant positive correlation between L_X_/L_bol_ and corotation radius, suggesting that the observed X-ray luminosities are regulated by centrifugal stripping of the stellar coronae. The period-mass relationship in NGC 6530 is broadly similar to that of the Orion Nebula Cluster (ONC), but the slope of the relationship among the slowest rotators differs from that in the ONC and other young clusters. We show that the slope of the period-mass relationship for the slowest rotators can be used as a proxy for the age of a young cluster, and we argue that NGC 6530 may be slightly younger than the ONC, making it a particularly important touchstone for models of angular momentum evolution in young, low-mass stars.