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2931. Class I methanol maser catalog
ID:
ivo://CDS.VizieR/J/AZh/89/611
Title:
Class I methanol maser catalog
Short Name:
J/AZh/89/611
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have revised the Astro Space Center catalog of Class I methanol masers detected in starforming regions (MMI/SFR), mainly at 44GHz, and created a new electronic version of the catalog. Currently, the catalog contains 206 objects, selected from publications through 2011 inclusive. The data from the survey of Chen et al. (2011, Cat. J/ApJS/196/9), performed specifically for objects EGO, which form a new specific catalog, are not included. The MMI/SFR objects were identified with emission and absorption objects in the near IR, detected during the MSX and Spitzer space missions. Seventy-one percent of Class I methanol masers that emit at 44GHz and fall within the Galactic longitude range surveyed by Spitzer (GLIMPSE) are identified with Spitzer Dark Clouds (SDCs), and 42% with Extended Green Objects (EGOs). It is possible that Class I methanol masers arise in isolated, self-gravitating clumps, such as SDCs, at certain stages of their evolution. A sample of SDCs is proposed as a new target list for Class I methanol maser searches. A detailed statistical analysis was carried out, taking into account the characteristics of the regions of MMI/SFR formation presented in the catalog.
2932. Class 0 sources continuum subtracted UV-tables
ID:
ivo://CDS.VizieR/J/A+A/590/A33
Title:
Class 0 sources continuum subtracted UV-tables
Short Name:
J/A+A/590/A33
Date:
21 Oct 2021
Publisher:
CDS
Description:
The physical structure of deeply-embedded low-mass protostars (Class 0) on scales of less than 300AU is still poorly constrained. While molecular line observations demonstrate the presence of disks with Keplerian rotation toward a handful of sources, others show no hints of rotation. Determining the structure on small scales (few 100AU) is crucial for understanding the physical and chemical evolution from cores to disks. To determine the presence and characteristics of compact, disk-like structures in deeply-embedded low-mass protostars. A related goal is to investigate how the derived structure affects the determination of gas-phase molecular abundances on hot-core scales. Two models of the emission, a Gaussian disk intensity distribution and a parametrized power-law disk model, are fitted to sub-arcsecond resolution interferometric continuum observations of five Class 0 sources, including one source with a confirmed Keplerian disk. Prior to fitting the models to the de-projected real visibilities, the estimated envelope from an independent model and any companion source are subtracted. For reference, a spherically symmetric single power-law envelope is fitted to the larger scale (~1000AU) emission and investigated further for one of the sources on smaller scales.
2933. CLASS survey of radio sources
ID:
ivo://CDS.VizieR/VIII/72
Title:
CLASS survey of radio sources
Short Name:
VIII/72
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Cosmic Lens All-Sky Survey (CLASS) is an international collaborative program aimed at obtaining high-resolution radio images of over 10000 flat-spectrum radio sources in order to create the largest and best studied statistical sample of radio-loud gravitationally lensed systems. CLASS is aimed at identifying lenses where multiple images are formed from compact flat-spectrum radio sources, which should be easily identifiable in the radio maps (Browne et al., 2003MNRAS.341...13B). In four observing ``seasons'' from 1994-1999, CLASS has observed 13832 radio sources. When combined with the JVAS survey, the CLASS sample contains over 16,000 images. Using the GB6 and NVSS surveys, a complete statistical subset of 11685 sources has been constructed. These were selected from the NVSS 20-cm (Condon et al., 1998, Cat. <VIII/65>) and GB6 6-cm (Gregory et al., 1996, Cat. <VIII/40>) catalogues by the selection criteria: declination >0deg, |b|<10deg, S(6cm)>=30mJy, and spectral index between 6 and 20cm flatter than -0.5 (S proportional to frequency^+alpha^). The remaining sources were selected using earlier versions of these catalogues or with slightly relaxed versions of these criteria.
2934. CLASSy: CARMA obs. in L1451 region of Perseus
ID:
ivo://CDS.VizieR/J/ApJ/830/127
Title:
CLASSy: CARMA obs. in L1451 region of Perseus
Short Name:
J/ApJ/830/127
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a 3mm spectral line and continuum survey of L1451 in the Perseus Molecular Cloud. These observations are from the CARMA Large Area Star Formation Survey (CLASSy), which also imaged Barnard 1, NGC1333, Serpens Main, and Serpens South. L1451 is the survey region with the lowest level of star formation activity-it contains no confirmed protostars. HCO^+^, HCN, and N_2_H^+^ (J=1->0) are all detected throughout the region, with HCO^+^ being the most spatially widespread, and molecular emission seen toward 90% of the area above N(H_2_) column densities of 1.9x10^21^cm^-2^. HCO^+^ has the broadest velocity dispersion, near 0.3km/s on average, compared with ~0.15km/s for the other molecules, thus representing a range of subsonic to supersonic gas motions. Our non-binary dendrogram analysis reveals that the dense gas traced by each molecule has a similar hierarchical structure, and that gas surrounding the candidate first hydrostatic core (FHSC), L1451-mm, and other previously detected single-dish continuum clumps has similar hierarchical structure; this suggests that different subregions of L1451 are fragmenting on the pathway to forming young stars. We determined that the three-dimensional morphology of the largest detectable dense-gas structures was relatively ellipsoidal compared with other CLASSy regions, which appeared more flattened at the largest scales. A virial analysis shows that the most centrally condensed dust structures are likely unstable against collapse. Additionally, we identify a new spherical, centrally condensed N_2_H^+^ feature that could be a new FHSC candidate. The overall results suggest that L1451 is a young region starting to form its generation of stars within turbulent, hierarchical structures.
2935. CLASXS: X-ray catalog
ID:
ivo://CDS.VizieR/J/AJ/128/1501
Title:
CLASXS: X-ray catalog
Short Name:
J/AJ/128/1501
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the X-ray catalog and basic results from our Chandra Large Area Synoptic X-ray Survey (CLASXS) of the Lockman Hole-Northwest (LHNW) field. Our nine ACIS-I fields cover a contiguous solid angle of 0.4{deg}^2^ and reach fluxes of 5x10^-16^ergs/cm^2^/s (0.4-2keV) and 3x10^-15^ergs/cm^2^/s (2-8keV). Our survey bridges the gap between ultradeep pencil-beam surveys, such as the Chandra Deep Fields (CDFs), and shallower, large-area surveys, allowing a better probe of the X-ray sources that contribute most of the 2-10keV cosmic X-ray background (CXB). We find a total of 525 X-ray point sources and four extended sources.
2936. Cl 1103.7-1245 at z=0.96: spectroscopic catalog
ID:
ivo://CDS.VizieR/J/A+A/544/A104
Title:
Cl 1103.7-1245 at z=0.96: spectroscopic catalog
Short Name:
J/A+A/544/A104
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present new spectroscopic observations in a field containing the highest redshift cluster of the ESO Distant Cluster Survey (EDisCS). We measure galaxy redshifts and determine the velocity dispersions of the galaxy structures located in this field. Together with the main cluster Cl 1103.7-1245 (z=0.9580; {sigma}_clus_=522+/-111km/s) we find a secondary structure at z=0.9830, Cl 1103.7-1245c. We then characterize the galaxy properties in both systems. These new spectroscopic observations for Cl 1103.7-1245 complement the previous analysis of Milvang-Jensen et al. (2008, Cat. J/A+A/482/419), whose observations targetted z=0.70.
2937. CLEAR. II. SFRs of quiescent galaxies
ID:
ivo://CDS.VizieR/J/ApJ/898/171
Title:
CLEAR. II. SFRs of quiescent galaxies
Short Name:
J/ApJ/898/171
Date:
16 Mar 2022 00:57:30
Publisher:
CDS
Description:
The origin of the correlations between mass, morphology, quenched fraction, and formation history in galaxies is difficult to define, primarily due to the uncertainties in galaxy star formation histories (SFHs). SFHs are better constrained for higher redshift galaxies, observed closer to their formation and quenching epochs. Here we use "nonparametric" SFHs and a nested sampling method to derive constraints on the formation and quenching timescales of quiescent galaxies at 0.7<z<2.5. We model deep HST grism spectroscopy and photometry from the CLEAR (CANDELS Ly{alpha} Emission at Reionization) survey. The galaxy formation redshifts, z50 (defined as the point where they had formed 50% of their stellar mass) range from z_50_~2 (shortly prior to the observed epoch) up to z_50_~5-8. We find that early formation redshifts are correlated with high stellar-mass surface densities, log{Sigma}_1_/(M_{sun}_kpc^-2^)>10.25, where {Sigma}_1_ is the stellar mass within 1pkpc (proper kpc). Quiescent galaxies with the highest stellar-mass surface density, log{Sigma}_1_/(M_{sun}_kpc^-2^)>10.25, show a minimum formation redshift: all such objects in our sample have z_50_>2.9. Quiescent galaxies with lower surface density, log{Sigma}_1_/(M_{sun}_kpc^-2^)=9.5-10.25, show a range of formation epochs (z_50_~1.5-8), implying these galaxies experienced a range of formation and assembly histories. We argue that the surface density threshold log{Sigma}_1_/(M_{sun}_kpc^-2^)>10.25 uniquely identifies galaxies that formed in the first few Gyr after the big bang, and we discuss the implications this has for galaxy formation models.
2938. ClG 0217+70 radio images
ID:
ivo://CDS.VizieR/J/A+A/656/A154
Title:
ClG 0217+70 radio images
Short Name:
J/A+A/656/A154
Date:
21 Mar 2022 09:15:55
Publisher:
CDS
Description:
Megaparsec-scale radio sources in the form of halos and relics are often detected in dynamically disturbed galaxy clusters. Although they are associated with merger-induced turbulence and shocks, respectively, their formation is not fully understood. Aims. We aim to identify the mechanisms responsible for particle acceleration and magnetic field amplification in the halo and relics of the galaxy cluster ClG 0217+70. We observed ClG 0217+70 with LOFAR at 141MHz and with VLA at 1.5GHz, and we combined these observations with VLA 1.4GHz archival data to study the morphological and spectral properties of the diffuse sources.We added Chandra archival data to examine the thermal and non-thermal properties of the halo. Our LOFAR and VLA data confirm the presence of a giant radio halo in the cluster centre and multiple relics in the outskirts. The radio and X-ray emission from the halo are correlated, implying a tight relation between the thermal and non-thermal components. The diuse radio structure in the south-east, with a projected size of 3.5Mpc, is the most extended radio relic detected to date. The spectral index across the relic width steepens towards the cluster centre, suggesting electron ageing in the post-shock regions. The shock Mach numbers for the relics derived from the spectral index map range between 2.0 and 3.2. However, the integrated spectral indices lead to increasingly high Mach numbers for the relics farther from the cluster centre. This discrepancy could be because the relation between injection and integrated spectra does not hold for distant shocks, suggesting that the cooling time for the radioemitting electrons is longer than the crossing time of the shocks. The variations in the surface brightness of the relics and the low Mach numbers imply that the radio-emitting electrons are re-accelerated from fossil plasma that could originate in active galactic nuclei.
2939. Cl0939+4713 H{alpha} z~0.4 star-forming galaxies
ID:
ivo://CDS.VizieR/J/MNRAS/458/3443
Title:
Cl0939+4713 H{alpha} z~0.4 star-forming galaxies
Short Name:
J/MNRAS/458/3443
Date:
21 Oct 2021
Publisher:
CDS
Description:
Cluster star-forming galaxies are found to have an excess of far-infrared emission relative to H{alpha}, when compared to those in the field, which could be caused by intense active galactic nuclei (AGN) activity, dust and/or declining star formation histories. Here we present spectroscopic observations of H{alpha} emitters in the Cl 0939+4713 (Abell 851) super-cluster at z=0.41, using AF2+ WYFFOS on the William Herschel Telescope. We measure [OII], H{beta}, [OIII], H{alpha} and [NII] for a sample of 119 H{alpha} emitters in and around the cluster. We find that 17+/-5 per cent of the H{alpha} emitters are AGN, irrespective of environment. For star-forming galaxies, we obtain Balmer decrements, metallicities and ionization parameters with different methods, individually and by stacking. We find a strong mass-metallicity relation at all environments, with no significant dependence on environment. The ionization parameter declines with increasing stellar mass for low-mass galaxies. H{alpha} emitters residing in intermediate environments show the highest ionization parameters (along with high [OIII]/H{alpha} and high [OIII]/[OII] line ratios, typically twice as large as in the highest and lowest densities), which decline with increasing environmental density. Dust extinction (A_H{alpha}_) correlates strongly with stellar mass, but also with environmental density. Star-forming galaxies in the densest environments are found to be significantly dustier (A_H{alpha}_~=1.5-1.6) than those residing in the lowest density environments (A_H{alpha}_~=0.6), deviating significantly from what would be predicted given their stellar masses.
2940. 3C295 LOFAR, MERLIN and VLA images
ID:
ivo://CDS.VizieR/J/A+A/658/A10
Title:
3C295 LOFAR, MERLIN and VLA images
Short Name:
J/A+A/658/A10
Date:
02 Feb 2022 13:43:44
Publisher:
CDS
Description:
3C295 is a bright, compact steep spectrum source with a well-studied integrated radio spectral energy distribution (SED) from 132MHz to 15GHz. However, spatially resolved spectral studies have been limited due to a lack of high resolution images at low radio frequencies. These frequencies are crucial for measuring absorption processes, and anchoring the overall spectral modelling of the radio SED. In this paper, we use International LOw-Frequency ARray (LOFAR) Telescope (ILT) observations of 3C295 to study its spatially resolved spectral properties with sub-arcsecond resolution at 132MHz. Combining our new 132MHz observation with archival data at 1.6GHz, 4.8GHz, and 15GHz, we are able to carryout a resolved radio spectral analysis. The spectral properties of the hotspots provides evidence for low frequency flattening. In contrast, the spectral shape across the lobes is consistent with a Jaffe-Perola spectral ageing model. Usingthe integrated spectral information for each component, we then fitted low-frequency absorption models to the hotspots,finding that both free-free absorption and synchrotron self-absorption models provide a better fit to the data than a standard power law. Although we can say there is low-frequency absorption present in the hot spots of 3C295, future observations with the Low Band Antenna of the ILT at 55MHz may allow us to distinguish the type of absorption.

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