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391. DEIMOS 10K spectroscopic survey in COSMOS field
ID:
ivo://CDS.VizieR/J/ApJ/858/77
Title:
DEIMOS 10K spectroscopic survey in COSMOS field
Short Name:
J/ApJ/858/77
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of 10718 objects in the COSMOS field, observed through multi-slit spectroscopy with the Deep Imaging Multi-Object Spectrograph (DEIMOS) on the Keck II telescope in the wavelength range ~5500-9800{AA}. The catalog contains 6617 objects with high-quality spectra (two or more spectral features), and 1798 objects with a single spectroscopic feature confirmed by the photometric redshift. For 2024 typically faint objects, we could not obtain reliable redshifts. The objects have been selected from a variety of input catalogs based on multi-wavelength observations in the field, and thus have a diverse selection function, which enables the study of the diversity in the galaxy population. The magnitude distribution of our objects is peaked at I_AB_~23 and K_AB_~21, with a secondary peak at K_AB_~24. We sample a broad redshift distribution in the range 0<z<6, with one peak at z~1, and another one around z~4. We have identified 13 redshift spikes at z>0.65 with chance probabilities <4x10^-4^, some of which are clearly related to protocluster structures of sizes >10Mpc. An object-to-object comparison with a multitude of other spectroscopic samples in the same field shows that our DEIMOS sample is among the best in terms of fraction of spectroscopic failures and relative redshift accuracy. We have determined the fraction of spectroscopic blends to about 0.8% in our sample. This is likely a lower limit and at any rate well below the most pessimistic expectations. Interestingly, we find evidence for strong lensing of Ly{alpha} background emitters within the slits of 12 of our target galaxies, increasing their apparent density by about a factor of 4.
392. 1 Del spectroscopy
ID:
ivo://CDS.VizieR/J/A+A/587/A22
Title:
1 Del spectroscopy
Short Name:
J/A+A/587/A22
Date:
21 Oct 2021
Publisher:
CDS
Description:
Stable shell stars are ideal objects for studying basic physical principles of the formation of disks in Be stars. If these stars have a close unresolved visual companion, its contribution toward the modelling of the disk cannot be overlooked, as is sometimes done. The study aims to spectroscopically resolve close visual binary Be (shell) star 1 Del, which up to now was only resolved by speckle or micrometric measurements. The integral field spectroscopy obtained by the SINFONI spectrograph at the VLT telescope in the European Southern Observatory (ESO) in the infrared region was used; we supplemented these observations with visual spectroscopy with the Perek Telescope at the Ondrejov Observatory. Spectra of 1 Del were successfully resolved, and, for the first time, spectra of 1 Del B were obtained. We found that 1 Del A is a Be/shell star, while 1 Del B is not an emission-line object.
393. Delta Scuti stars
ID:
ivo://CDS.VizieR/J/A+AS/144/469
Title:
Delta Scuti stars
Short Name:
J/A+AS/144/469
Date:
21 Oct 2021
Publisher:
CDS
Description:
An extensive and up-dated list of {delta} Sct stars is presented here. More than 500 papers, published during the last few years, have been revised and 341 new variables have been added to our last list, six years ago. This catalogue is intended to be a comprehensive review on the observational characteristics of all the {delta} Sct stars known until now, including stars contained in earlier catalogues together with other new discovered variables, covering information published until January 2000. In summary, 636 variables, 1149 references and 182 individual notes are presented in this new list.
394. Dense parts of outflows toward massive cores
ID:
ivo://CDS.VizieR/J/other/ChA+A/36.238
Title:
Dense parts of outflows toward massive cores
Short Name:
J/other/ChA+A/36
Date:
21 Oct 2021
Publisher:
CDS
Description:
A set of samples of 13 massive star-forming cores were observed in SiO (2-1), CH_3_OH (2-1) and C^34^S (2-1) thermal lines. Nine of these cores were detected in all three lines. Among the nine SiO detections, three were new detections, and relatively faint. Most of the lines have wide wings, which might be interpreted as the evidence of ongoing energetic outflows in the cores.
395. Dense warm ionized medium in the inner Galaxy
ID:
ivo://CDS.VizieR/J/A+A/651/A59
Title:
Dense warm ionized medium in the inner Galaxy
Short Name:
J/A+A/651/A59
Date:
22 Feb 2022
Publisher:
CDS
Description:
Ionized interstellar gas is an important component of the interstellar medium and its lifecycle. The recent evidence for a widely distributed highly ionized warm interstellar gas with a density intermediate between the warm ionized medium (WIM) and compact HII regions suggests that there is a major gap in our understanding of the interstellar gas. Our goal is to investigate the properties of the dense warm ionized medium in the Milky Way using spectrally resolved SOFIA GREAT [NII] 205um fine-structure lines and Green Bank Telescope hydrogen radio recombination lines (RRL) data, supplemented by spectrally unresolved Herschel PACS [NII] 122um data, and spectrally resolved ^12^CO. We observed eight lines of sight (LOS) in the 20{deg}<l<30{deg}region in the Galactic plane. We spectrally unresolved Herschel PACS [NII] 122um data, and spectrally resolved ^12^CO. Methods. We observed eight lines of sight (LOS) in the 20{deg}<l<30{deg}region in the Galactic plane. We analyzed spectrally resolved lines of [NII] at 205um and RRL observations, along with the spectrally unresolved Herschel PACS 122um emission, using excitation and radiative transfer models to determine the physical parameters of the dense warm ionized medium. We derived the kinetic temperature, as well as the thermal and turbulent velocity dispersions from the [NII] and RRL linewidths. The regions with [NII] 205um emission are characterized by electron densities, n(e)~10-35cm^-3^, temperatures range from 3400 to 8500K, and nitrogen column densities N(N^+^)~7x10^16^ to 3x10^17^cm^-2^. The ionized hydrogen column densities range from 6x10^20^ to 1.7x10^21^cm^-2^ and the fractional nitrogen ion abundance x(N^+^)~1.1x10^-4^ to 3.0x10^-4^, implying an enhanced nitrogen abundance at a distance ~4.3kpc from the Galactic Center. The [NII] 205um emission lines coincide with CO emission, although often with an offset in velocity, which suggests that the dense warm ionized gas is located in, or near, star-forming regions, which themselves are associated with molecular gas. These dense ionized regions are found to contribute >~50% of the observed [CII] intensity along these LOS. The kinetic temperatures we derive are too low to explain the presence of N^+^ resulting from electron collisional ionization and/or proton charge transfer of atomic nitrogen. Rather, these regions most likely are ionized by extreme ultraviolet (EUV) radiation from nearby star-forming regions or as a result of EUV leakage through a clumpy and porous interstellar medium.
396. Detected CH_2_ spectra
ID:
ivo://CDS.VizieR/J/A+A/647/A42
Title:
Detected CH_2_ spectra
Short Name:
J/A+A/647/A42
Date:
19 Jan 2022 13:29:47
Publisher:
CDS
Description:
The N_KaKc_=4_04_-3_13_ transitions of ortho-CH_2_ between 68 and 71GHz were first detected toward the Orion-KL and W51 Main star-forming regions. Given their high upper level energies (225K) above the ground state, they were naturally thought to arise in dense, hot molecular cores near newly formed stars. However, this has not been confirmed by further observations of these lines and their origin has remained unclear. Quite in general, only a paucity of observational data exist for CH_2_ and, while astrochemically an important compound, its actual occurrence in astronomical sources is poorly constrained. In this work, we aim to investigate the nature of the elusive CH_2_ emission and address its association with hot cores and examine alternative possibilities for its origin. Owing to its importance in carbon chemistry, we also extend the search for CH_2_ lines by observing an assortment of regions guided by the hypothesis that the observed CH_2_ emission likely arises from the hot gas environment of photodissociation regions (PDRs). We carried out observations using, first, the Kitt Peak 12m telescope to verify the original detection of CH_2_ toward different positions in the central region of Orion Molecular Cloud 1. These were followed-up by deep integrations using the higher angular resolution of the Onsala 20 m telescope. We have also searched for the N_KaKc_=2_12_-3_03_ transitions of para-CH_2_ between 440-445GHz toward the Orion giant molecular cloud complex using the APEX 12m telescope. We also obtained auxiliary data for carbon recombination lines with the Effelsberg 100m telescope and employed archival far infrared data. Our and other recent observations of the Orion region reported here, rule out an association with hot and dense gas. We find that the distribution of the CH_2_ emission follows closely that of the [CII] 158 um emission while CH_2_ is undetected toward the hot core itself. The observations suggest that its extended emission rather arises from hot but dilute layers of PDRs, but not from the denser parts of such regions, in particular the Orion Bar. This hypothesis was corroborated by comparisons of the observed CH_2_ line profiles with those of carbon radio recombination lines (CRRLs), well known PDR tracers. In addition, we report the detection of the 70GHz fine-, and hyperfine structure components of ortho-CH_2_ toward the W51 E, W51 M, W51 N, W49 N, W43, W75 N, DR21, and S140 star-forming regions, and three of the N_KaKc_=4_04_-3_13_ fine- and hyperfine structure transitions between 68-71GHz toward W3 IRS5. While we have no information on CH_2_'s spatial distribution in these regions, except for W51, we again see a correspondence of the profiles of CH_2_ lines with those of CRRLs. We see stronger CH_2_ emission toward the extended HII region W51 M than toward the much more massive and denser W51 E and N regions, strongly supporting an origin of CH_2_ in extended dilute gas. We also report the non-detection of the 2_12_-3_03_ transitions of para-CH_2_ toward Orion. Furthermore, using a non-LTE radiative transfer analysis, we can constrain the gas temperatures and H_2_ density to (163+/-26)K and (3.4+/-0.3)x10^3^cm^-3^, respectively, for the 68-71GHz ortho-CH_2_ transitions toward W3 IRS5, for which we have the highest quality data set. This analysis confirms our hypothesis that CH_2_ originates in warm and dilute PDR layers. Our analysis suggests that for the excitation conditions under the physical conditions that prevail in such an environment, these lines are masering, with weak level inversion. The resulting amplification of the lines' spontaneous emission greatly aides their detection.
397. Deuteration in massive star formation process
ID:
ivo://CDS.VizieR/J/A+A/575/A87
Title:
Deuteration in massive star formation process
Short Name:
J/A+A/575/A87
Date:
21 Oct 2021
Publisher:
CDS
Description:
An ever growing number of observational and theoretical evidence suggests that the deuterated fraction (column density ratio between a species containing D and its hydrogenated counterpart, Dfrac) is an evolutionary indicator both in the low- and the high-mass star formation process. However, the role of surface chemistry in these studies has not been quantified from an observational point of view. In order to compare how the deuterated fractions of species formed only in the gas and partially or uniquely on grain surfaces evolve with time, we observed rotational transitions of CH_3_OH, ^13^CH_3_OH, CH_2_DOH, CH_3_OD at 3 and 1.3mm, and of NH_2_D at 3mm with the IRAM-30m telescope, and the inversion transitions (1,1) and (2,2) of NH_3_ with the GBT, towards most of the cores already observed by Fontani et al. (2011A&A...529L...7F, 2014MNRAS.440..448F) in N_2_H^+^, N_2_D^+^, HNC, DNC. NH_2_D is detected in all but two cores, regardless of the evolutionary stage. Dfrac(NH_3_) is on average above 0.1, and does not change significantly from the earliest to the most evolved phases, although the highest average value is found in the protostellar phase (~0.3). Few lines of CH_2_DOH and CH_3_OD are clearly detected, and only towards protostellar cores or externally heated starless cores. This work clearly confirms an expected different evolutionary trend of the species formed exclusively in the gas (N_2_D^+^ and N_2_H^+^) and those formed partially (NH_2_D and NH_3_) or totally (CH_2_DOH and CH_3_OH) on grain mantles. The study also reinforces the idea that Dfrac(N_2_H^+^) is the best tracer of massive starless cores, while high values of Dfrac(CH_3_OH) seem rather good tracers of the early protostellar phases, at which the evaporation/sputtering of the grain mantles is most efficient.
398. 3D-HST Survey: grism spectra master catalog
ID:
ivo://CDS.VizieR/J/ApJS/225/27
Title:
3D-HST Survey: grism spectra master catalog
Short Name:
J/ApJS/225/27
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present reduced data and data products from the 3D-HST survey, a 248-orbit HST Treasury program. The survey obtained WFC3 G141 grism spectroscopy in four of the five CANDELS fields: AEGIS, COSMOS, GOODS-S, and UDS, along with WFC3 H_140_ imaging, parallel ACS G800L spectroscopy, and parallel I_814_ imaging. In a previous paper, we presented photometric catalogs in these four fields and in GOODS-N, the fifth CANDELS field. Here we describe and present the WFC3 G141 spectroscopic data, again augmented with data from GO-1600 in GOODS-N (PI: B. Weiner). We developed software to automatically and optimally extract interlaced two-dimensional (2D) and one-dimensional (1D) spectra for all objects in the Skelton+ (2014, J/ApJS/214/24) photometric catalogs. The 2D spectra and the multi-band photometry were fit simultaneously to determine redshifts and emission line strengths, taking the morphology of the galaxies explicitly into account. The resulting catalog has redshifts and line strengths (where available) for 22548 unique objects down to JH_IR_<=24 (79609 unique objects down to JH_IR<=26). Of these, 5459 galaxies are at z>1.5 and 9621 are at 0.7<z<1.5, where H{alpha} falls in the G141 wavelength coverage. The typical redshift error for JH_IR_<=24 galaxies is {sigma}_z_~0.003x(1+z), i.e., one native WFC3 pixel. The 3{sigma} limit for emission line fluxes of point sources is 2.1x10^-17^erg/s/cm^2^.
399. DIB and NaD spectra of 3 nearby stars
ID:
ivo://CDS.VizieR/J/A+A/591/A20
Title:
DIB and NaD spectra of 3 nearby stars
Short Name:
J/A+A/591/A20
Date:
21 Oct 2021
Publisher:
CDS
Description:
Diffuse interstellar absorption bands (DIBs) of largely unknown chemical origin are regularly observed primarily in distant early-type stars. More recently, detections in nearby late-type stars have also been claimed. These stars' spectra are dominated by stellar absorption lines. Specifically, strong interstellar atomic and DIB absorption has been reported in tau Boo. We test these claims by studying the strength of interstellar absorption in high-resolution TIGRE spectra of the nearby stars tau Boo, HD 33608, and alpha CrB. We focus our analysis on a strong DIB located at 5780.61{AA} and on the absorption of interstellar Na. First, we carry out a differential analysis by comparing the spectra of the highly similar F-stars, tau Boo and HD 33608, whose light, however, samples different lines of sight. To obtain absolute values for the DIB absorption, we compare the observed spectra of tau Boo, HD 33608, and alpha CrB to PHOENIX models and carry out basic spectral modeling based on Voigt line profiles.
400. DIB in VLT-FLAMES Tarantula Survey
ID:
ivo://CDS.VizieR/J/A+A/550/A108
Title:
DIB in VLT-FLAMES Tarantula Survey
Short Name:
J/A+A/550/A108
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Tarantula Nebula (a.k.a. 30 Dor) is a spectacular star-forming region in the Large Magellanic Cloud (LMC), seen through gas in the Galactic disc and halo. Diffuse interstellar bands (DIBs) offer a unique probe of the diffuse, cool-warm gas in these regions. The aim is to use DIBs as diagnostics of the local interstellar conditions, whilst at the same time deriving properties of the yet-unknown carriers of these enigmatic spectral features. Spectra of over 800 early-type stars from the Very Large Telescope Flames Tarantula Survey (VFTS) were analysed. Maps were created, separately, for the Galactic and LMC absorption in the DIBs at 4428 and 6614{AA} and - in a smaller region near the central cluster R 136 - neutral sodium (the NaI D doublet); we also measured the DIBs at 5780 and 5797{AA}.