- ID:
- ivo://CDS.VizieR/J/A+A/617/A38
- Title:
- The hydrogen gas outflow in 3C236
- Short Name:
- J/A+A/617/A38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The energetic feedback that is generated by radio jets in active galactic nuclei (AGNs) has been suggested to be able to produce fast outflows of atomic hydrogen (HI) gas which can be studied in absorption at high spatial resolution. We have used the Very Large Array (VLA) and a global very-long-baseline-interferometry (VLBI) array to locate and study in detail the HI outflow discovered with the Westerbork Synthesis Radio Telescope (WSRT) in the restarted radio galaxy 3C 236. Based on the VLA data, the presence of a blue-shifted wing of the HI with a width of ~1000km/s. This HI outflow is partially recovered by the VLBI observation. In particular, we detect four clouds with masses of 0.28-1.5x10^4^M_{sun}_ with VLBI that do not follow the regular rotation of most of the HI. Three of these clouds are located, in projection, against the nuclear region on scales of <~40pc, while the fourth is cospatial to the southeast lobe at a projected distance of ~270pc. Their velocities are between 150 and 640km/s blueshifted with respect to the velocity of the disk-related HI. These findings suggest that the outflow is at least partly formed by clouds, as predicted by some numerical simulations, and that it originates already in the inner (few tens of pc) region of the radio galaxy. Our results indicate that the entire outflow might consist of many clouds, possibly with comparable properties as those clearly detected, but also distributed at larger radii from the nucleus where the lower brightness of the lobe does not allow us to detect them. However, we cannot rule out a diffuse component of the outflow. Because 3C 236 is a low excitation radio galaxy, it is less likely that the optical AGN is able to produce strong radiative winds. This leaves the radio jet as the main driver for the HI outflow.
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- ID:
- ivo://CDS.VizieR/J/ApJ/837/40
- Title:
- The MASSIVE survey. VI. Warm ionized gas.
- Short Name:
- J/ApJ/837/40
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first systematic investigation of the existence, spatial distribution, and kinematics of warm ionized gas as traced by the [OII]3727{AA} emission line in 74 of the most massive galaxies in the local universe. All of our galaxies have deep integral-field spectroscopy from the volume- and magnitude-limited MASSIVE survey of early-type galaxies with stellar mass log(M_*_/M_{sun}_)>11.5 (M_K_<-25.3mag) and distance D<108Mpc. Of the 74 galaxies in our sample, we detect warm ionized gas in 28, which yields a global detection fraction of 38+/-6% down to a typical [OII] equivalent width limit of 2{AA}. MASSIVE fast rotators are more likely to have gas than MASSIVE slow rotators with detection fractions of 80+/-10% and 28+/-6%, respectively. The spatial extents span a wide range of radii (0.6-18.2kpc; 0.1-4R_e_), and the gas morphologies are diverse, with 17/28~61+/-9% being centrally concentrated, 8/28~29+/-9% exhibiting clear rotation out to several kiloparsecs, and 3/28~11+/-6% being extended but patchy. Three out of four fast rotators show kinematic alignment between the stars and gas, whereas the two slow rotators with robust kinematic measurements available exhibit kinematic misalignment. Our inferred warm ionized gas masses are roughly ~10^5^M_{sun}_. The emission line ratios and radial equivalent width profiles are generally consistent with excitation of the gas by the old underlying stellar population. We explore different gas origin scenarios for MASSIVE galaxies and find that a variety of physical processes are likely at play, including internal gas recycling, cooling out of the hot gaseous halo, and gas acquired via mergers.
- ID:
- ivo://CDS.VizieR/J/ApJ/784/3
- Title:
- The PAWS catalogs of GMCs and islands in M51
- Short Name:
- J/ApJ/784/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using data from the PdBI Arcsecond Whirlpool Survey (PAWS), we have generated the largest extragalactic giant molecular cloud (GMC) catalog to date, containing 1507 individual objects. GMCs in the inner M51 disk account for only 54% of the total ^12^CO(1-0) luminosity of the survey, but on average they exhibit physical properties similar to Galactic GMCs. We do not find a strong correlation between the GMC size and velocity dispersion, and a simple virial analysis suggests that ~30% of GMCs in M51 are unbound. We have analyzed the GMC properties within seven dynamically motivated galactic environments, finding that GMCs in the spiral arms and in the central region are brighter and have higher velocity dispersions than inter-arm clouds. Globally, the GMC mass distribution does not follow a simple power-law shape. Instead, we find that the shape of the mass distribution varies with galactic environment: the distribution is steeper in inter-arm region than in the spiral arms, and exhibits a sharp truncation at high masses for the nuclear bar region. We propose that the observed environmental variations in the GMC properties and mass distributions are a consequence of the combined action of large-scale dynamical processes and feedback from high-mass star formation. We describe some challenges of using existing GMC identification techniques for decomposing the ^12^CO(1-0) emission in molecule-rich environments, such as M51's inner disk.
- ID:
- ivo://CDS.VizieR/J/A+A/623/A21
- Title:
- Thermal dust modified black-body parameter maps
- Short Name:
- J/A+A/623/A21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Planck data releases have provided the community with submillimetre and full-sky radio observations at unprecedented resolutions. We make use of the Planck 353, 545, and 857GHz maps alongside the IRAS 3000 GHz map. These maps contain information on the cosmic microwave background (CMB), cosmic infrared background (CIB), extragalactic point sources, and diffuse thermal dust emission. We aim to determine the modified black-body (MBB) model parameters of thermal dust emission in total intensity and produce all-sky maps of pure thermal dust, having separated this Galactic component from the CMB and CIB. This separation is completed using a new, sparsity-based, parametric method, Parameter Recovery Exploiting Model Informed Sparse Estimates (premise). The method is comprised of three main stages: 1) filtering the raw data to reduce the effect of the CIB on the MBB fit; 2) fitting an MBB model to the filtered data across super-pixels of various sizes determined by the algorithm itself; and 3) refining these super-pixel estimates into full-resolution maps of the MBB parameters. We present our maps of MBB temperature, spectral index, and optical depth at 5-arcmin resolution and compare our estimates to those of GNILC and to the two-step MBB fit presented by the Planck collaboration in 2013. By exploiting sparsity we avoid the need for smoothing, enabling us to produce the first full-resolution MBB parameter maps from intensity measurements of thermal dust emission.We consider the premise parameter estimates to be competitive with the existing state-of-the-art solutions, outperforming these methods within low signal-to-noise regions as we account for the CIB without removing thermal dust emission through oversmoothing.
- ID:
- ivo://CDS.VizieR/J/AZh/71/37
- Title:
- Thermal Methanol from 33 Clouds at 48 GHz
- Short Name:
- J/AZh/71/37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A search for thermal emission in the 1_0_-0_0_A^+^ methanol line was made at a frequency of 48.4GHz toward many celestial molecular clouds. The line was found in 33 clouds, and the methanol abundance varied over a large interval from 10^-9^ to 10^-7^.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A111
- Title:
- The rotational spectrum of acrylamide
- Short Name:
- J/A+A/659/A111
- Date:
- 15 Mar 2022 06:07:15
- Publisher:
- CDS
- Description:
- Numerous complex organic molecules have been detected in the universe and among them are amides, which are considered as prime models for species containing a peptide linkage. In its backbone, acrylamide (CH_2_CHC(O)NH_2_) bears not only the peptide bond, but also the vinyl functional group that is a common structural feature in many interstellar compounds. This makes acrylamide an interesting candidate for searches in the interstellar medium. In addition, a tentative detection of the related molecule propionamide (C_2_H_5_C(O)NH_2_) has been recently claimed toward Sgr B2(N). The aim of this work is to extend the knowledge of the laboratory rotational spectrum of acrylamide to higher frequencies, which would make it possible to conduct a rigorous search for interstellar signatures of this amide using millimeter wave astronomy. We measured and analyzed the rotational spectrum of acrylamide between 75 and 480GHz. We searched for emission of acrylamide in the imaging spectral line survey ReMoCA performed with the Atacama Large Millimeter/submillimeter Array toward Sgr B2(N). We also searched for propionamide in the same source. The astronomical spectra were analyzed under the assumption of local thermodynamic equilibrium. We report accurate laboratory measurements and analyses of thousands of rotational transitions in the ground state and two excited vibrational states of the most stable syn form of acrylamide. In addition, we report an extensive set of rotational transitions for the less stable skew conformer. Tunneling through a low energy barrier between two symmetrically equivalent configurations has been revealed for this higher-energy species. Neither acrylamide nor propionamide were detected toward the two main hot molecular cores of Sgr B2(N). We did not detect propionamide either toward a position located to the east of the main hot core, thereby undermining the recent claim of its interstellar detection toward this position. We find that acrylamide and propionamide are at least 26 and 14 times less abundant, respectively, than acetamide toward the main hot core Sgr B2(N1S), and at least 6 and 3 times less abundant, respectively, than acetamide toward the secondary hot core Sgr B2(N2). A comparison with results of astrochemical kinetics model for related species suggests that acrylamide may be a few hundred times less abundant than acetamide, corresponding to a value that is at least an order of magnitude lower than the observational upper limits. Propionamide may be as little as only a factor of two less abundant than the upper limit derived toward Sgr B2(N1S). Lastly, the spectroscopic data presented in this work will aid future searches of acrylamide in space.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A99
- Title:
- The rotational spectrum of glycinamide
- Short Name:
- J/A+A/657/A99
- Date:
- 21 Mar 2022 09:35:44
- Publisher:
- CDS
- Description:
- Glycinamide (NH_2_CH_2_C(O)NH_2_) is considered to be one of the possible precursors of the simplest amino acid glycine. Its only rotational spectrum reported so far has been in the cm-wave region on a laser-ablation generated supersonic expansion sample. The aim of this work is to extend the laboratory spectrum of glycinamide into the millimetre wave region to support its searches in the interstellar medium and to perform the first check for its presence in the high-mass star forming region Sagittarius B2(N). Glycinamide was synthesised chemically and was studied with broadband rotational spectroscopy in the 90-329 GHz region with the sample in slow flow at 50{deg}C. Tunneling across a low energy barrier between two symmetry equivalent configurations of the molecule resulted in splitting of each vibrational state and many perturbations in associated rotational energy levels, requiring careful coupled state fits for each vibrational doublet. We searched for emission of glycinamide in the imaging spectral line survey ReMoCA performed with the Atacama Large Millimetre/submillimetre Array toward Sgr B2(N). The astronomical spectra were analysed under the assumption of local thermodynamic equilibrium. We report the first analysis of the mm-wave rotational spectrum of glycinamide, resulting in fitting to experimental measurement accuracy of over 1200 assigned and measured transition frequencies for the ground state tunneling doublet, of many lines for tunneling doublets for two singly excited vibrational states, and determination of precise vibrational separation in each doublet. We did not detect emission from glycinamide in the hot molecular core Sgr B2(N1S). We derived a column density upper limit of 1.5x10^16^cm^-2^, which implies that glycinamide is at least seven times less abundant than aminoacetonitrile and 1.8 times less abundant than urea in this source.
- ID:
- ivo://CDS.VizieR/J/A+A/646/A170
- Title:
- The Serpens filament 13CO, C18O and C17O datacubes
- Short Name:
- J/A+A/646/A170
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Serpens filament, a prominent elongated structure in a relatively nearby molecular cloud, is believed to be at an early evolutionary stage, so studying its physical and chemical properties can shed light on filament formation and early evolution. The main goal is to address the physical and chemical properties as well as dynamical state of the Serpens filament at a spatial resolution of ~0.07pc and a spectral resolution of ~0.1~km/s. We performed ^13^CO (1-0), C^18^O (1-0), C^17^O (1-0), ^13^CO (2-1), C^18^O (2-1), and C^17^O (2-1) imaging observations toward the Serpens filament with the IRAM-3 m and APEX telescopes. Widespread narrow ^13^CO (2-1) self-absorption is observed in this filament, causing the ^13^CO morphology to be different from the filamentary structure traced by C^18^O and C^17^O. Our excitation analysis suggests that the opacities of C^18^O transitions become higher than unity in most regions, and this analysis confirms the presence of widespread CO depletion. Further we show that the local velocity gradients have a tendency to be perpendicular to the filament's long axis in the outskirts and parallel to the large-scale magnetic field direction. The magnitudes of the local velocity gradients decrease toward the filament's crest. The observed velocity structure can be a result of gravity-driven accretion flows. The isochronic evolutionary track of the C^18^O freeze-out process indicates the filament is young with an age of <~2Myr. We propose that the Serpens filament is a newly-formed slightly-supercritical structure which appears to be actively accreting material from its ambient gas.
- ID:
- ivo://CDS.VizieR/J/A+A/401/873
- Title:
- The SMC in the Far Infrared
- Short Name:
- J/A+A/401/873
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ISOPHOT experiment onboard the ISO satellite generated a complete view of the Small Magellanic Cloud (SMC) at 170{mu}m with 1.5arcmin resolution. The map is analysed using an automated photometry program enabling accurate photometric characterization of the far infrared (FIR) emitting regions. In this paper, the sources detected at 170{mu}m are compared with those obtainable from the IRAS satellite data. For this purpose, the 12{mu}m, 25{mu}m, 60{mu}m, and 100{mu}m IRAS high resolution (HiRes) maps of the SMC are re-examined using the same method. In contrast to former studies, this provides an all-band ISO/IRAS source catalog which is no longer based on eyeball classification, but relies on an algorithm which is capable of automated, repeatable photometry, even for irregular sources. In the mid infrared IRAS bands numerous bright FIR emitting regions in the SMC are detected and classified: 73 sources are found at 12{mu}m, 135 at 25{mu}m (most of them with F{nu}<1.0Jy). All three FIR bands at 170{mu}m, 100{mu}m, and 60{mu}m reproduce the overall morphological structure of the SMC similarly well, in contrast to the 12{mu}m and 25{mu}m maps which only contain a limited number of extended sources and do not trace the main body of the SMC. 243 sources are detected in the ISO 170{mu}m map, 155 of them with F{nu}>=2.0Jy. Comparable numbers are found for the two FIR IRAS maps at 60{mu}m (384) and 100{mu}m (338) with fluxes up to 450Jy. 70 of the 243 170{mu}m sources are assigned a general SED type (cold , warm , i.e., <30K, >30K) for the first time. A comparison with earlier IRAS results suggests that many source flux densities in those studies have been under- or overestimated because of non-standardized fitting methods. Many sources with flux densities up to 40Jy listed in former catalogs cannot be identified in our data.
- ID:
- ivo://CDS.VizieR/J/AJ/150/40
- Title:
- The Spitzer c2d survey of clouds. XII. Perseus
- Short Name:
- J/AJ/150/40
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Spitzer Space Telescope mapped the Perseus molecular cloud complex with the Infrared Array Camera (IRAC) and the Multi-Band Imaging Photometer for Spitzer (MIPS) as part of the c2d Spitzer Legacy project. This paper combines the observations from both instruments giving an overview of low-mass star formation across Perseus from 3.6 to 70{mu}m. We provide an updated list of young stellar objects (YSOs) with new classifications and source fluxes from previous works, identifying 369 YSOs in Perseus with the Spitzer data set. By synthesizing the IRAC and MIPS maps of Perseus and building on the work of previous papers in this series, we present a current census of star formation across the cloud and within smaller regions. Sixty-seven percent of the YSOs are associated with the young clusters NGC 1333 and IC 348. The majority of the star formation activity in Perseus occurs in the regions around the clusters to the eastern and western ends of the cloud complex. The middle of the cloud is nearly empty of YSOs despite containing regions of high visual extinction. The western half of Perseus contains three-quarters of the total number of embedded YSOs (Class 0+I and Flat spectral energy distribution sources) in the cloud and nearly as many embedded YSOs as Class II and III sources. Class II and III objects greatly outnumber Class 0+I objects in eastern Perseus and IC 348. These results are consistent with previous age estimates for the clusters. Across the cloud, 56% of YSOs and 91% of the Class 0+I and Flat sources are in areas where A_v_>=5mag, indicating a possible extinction threshold for star formation.