- ID:
- ivo://CDS.VizieR/J/ApJ/884/66
- Title:
- The CGM-GRB study. I. GRB hosts at z~2-6
- Short Name:
- J/ApJ/884/66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent studies have revealed a dynamic interplay between the galaxy ecosystem and circumgalactic medium (CGM). We investigate the CGM at high redshifts (z>~2) by using bright afterglows of gamma-ray bursts (GRBs) as background sources. We compiled a sample of medium-resolution ({Delta}v<50km/s) and high signal-to-noise ratio (typical S/N~10) spectra from 27 GRB afterglows covering z~2-6, with six of them at z>~4. We analyzed the high- and low-ionization absorption features within +/-400km/s to extract the CGM and interstellar medium (ISM) kinematics. In the stacked spectra, high-ionization absorption profiles (e.g., CIV, SiIV) present significant absorption excess in their blue wings (v{<}-100km/s) relative to the red wings (v>100km/s). The stronger blue wings in high-ionization species are indicative of the presence of ubiquitous warm outflows in the GRB hosts at high redshifts. We used simple toy models to kinematically distinguish the CGM and ISM absorption and estimate the CGM mass and outflow velocity. We find tentative evidence of the evolution of the CGM metal mass by ~0.5dex between two redshift bins, each spanning 1 Gyr, z1: 2-2.7 and z2: 2.7-5. By comparing with past studies, we find that over the course of evolution of present-day galaxies with M_*_>10^10^M_{sun}_, the ratio of CIV mass in the CGM to the stellar mass remains fairly uniform, with log(M_CIV_/M_*_)~-4.5 within +/-0.5dex from z~4 to z~0, suggesting CGM-galaxy coevolution.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/606/A76
- Title:
- The ESO DIBs Large Exploration Survey
- Short Name:
- J/A+A/606/A76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The carriers of the diffuse interstellar bands (DIBs) are largely unidentified molecules ubiquitously present in the interstellar medium (ISM). After decades of study, two strong and possibly three weak near-infrared DIBs have recently been attributed to the C^+^_60_ fullerene based on observational and laboratory measurements. There is great promise for the identification of the over 400 other known DIBs, as this result could provide chemical hints towards other possible carriers. In an effort to systematically study the properties of the DIB carriers, we have initiated a new large-scale observational survey: the ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES). The main objective is to build on and extend existing DIB surveys to make a major step forward in characterising the physical and chemical conditions for a statistically significant sample of interstellar lines-of-sight, with the goal to reverse-engineer key molecular properties of the DIB carriers. EDIBLES is a filler Large Programme using the Ultraviolet and Visual Echelle Spectrograph at the Very Large Telescope at Paranal, Chile. It is designed to provide an observationally unbiased view of the presence and behaviour of the DIBs towards early-spectral-type stars whose lines-of-sight probe the diffuse-to-translucent ISM. Such a complete dataset will provide a deep census of the atomic and molecular content, physical conditions, chemical abundances and elemental depletion levels for each sightline. Achieving these goals requires a homogeneous set of high-quality data in terms of resolution (R~70000-100000), sensitivity (S/N up to 1000 per resolution element), and spectral coverage (305-1042nm), as well as a large sample size (100+ sightlines). In this first paper the goals, objectives and methodology of the EDIBLES programme are described and an initial assessment of the data is provided.
- ID:
- ivo://CDS.VizieR/J/AJ/149/162
- Title:
- The GBT 67-93.6GHz spectral line survey of Orion-KL
- Short Name:
- J/AJ/149/162
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a 67-93.6GHz spectral line survey of Orion-KL with the new 4mm Receiver on the Green Bank Telescope (GBT). The survey reaches unprecedented depths and covers the low-frequency end of the 3mm atmospheric window which has been relatively unexplored previously. The entire spectral-line survey is published electronically for general use by the astronomical community. The calibration and performance of the 4mm Receiver on the GBT is also summarized.
- ID:
- ivo://CDS.VizieR/J/A+A/556/A1
- Title:
- The 2.3GHz continuum survey of the GEM project
- Short Name:
- J/A+A/556/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Determining the spectral and spatial characteristics of the radio continuum of our Galaxy is an experimentally challenging endeavour for improving our understanding of the astrophysics of the interstellar medium. This knowledge has also become of paramount significance for cosmology, since Galactic emission is the main source of astrophysical contamination in measurements of the Cosmic Microwave Background radiation. In this paper we present the scope of the Galactic Emission Mapping (GEM) project and its results at 2.3GHz. Its observational program was conceived and developed to reveal the large scale properties of Galactic synchrotron radiation in total intensity and polarisation through a self-consistent set of radio continuum surveys between 408MHz and 10GHz. GEM's unique observational strategy and experimental design aim at the production of foreground templates in order to address the mutual inconsistencies between existing surveys.
- ID:
- ivo://CDS.VizieR/J/A+A/579/A29
- Title:
- The GUViCS FUV diffuse emission
- Short Name:
- J/A+A/579/A29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Virgo direction has been observed at many wavelengths in recent years, in particular in the ultraviolet with GALEX. The far ultraviolet (FUV) diffuse light detected by GALEX offers interesting information on the large scale distribution of Galactic dust, owing to the GALEX FUV band sensitivity and resolution. We aim to characterise the ultraviolet large scale distribution of diffuse emission in the Virgo direction. A map of this emission may become useful for various studies by identifying regions where dust affects observations by either scattering light or absorbing radiation.
- ID:
- ivo://CDS.VizieR/J/AJ/158/169
- Title:
- The hot gas exhaust of starburst engines in mergers
- Short Name:
- J/AJ/158/169
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using archival data from the Chandra X-ray telescope, we have measured the spatial extent of the hot interstellar gas in a sample of 49 nearby interacting galaxy pairs, mergers, and merger remnants. For systems with SFR>1 M_{sun}_/yr, the volume and mass of hot gas are strongly and linearly correlated with the star formation rate (SFR). This supports the idea that stellar/supernovae feedback dominates the production of hot gas in these galaxies. We compared the mass of X-ray-emitting hot gas M_X_(gas) with the molecular and atomic hydrogen interstellar gas masses in these galaxies (M_H2_ and M_HI_, respectively), using published carbon monoxide and 21 cm H I measurements. Systems with higher SFRs have larger M_X_(gas)/(M_H2_ + M_HI_) ratios on average, in agreement with recent numerical simulations of star formation and feedback in merging galaxies. The M_X_(gas)/(M_H2_ + M_HI_) ratio also increases with dust temperature on average. The ratio M_X_(gas)/SFR is anticorrelated with the Infrared Astronomical Satellite 60-100 {mu}m flux ratio and with the Spitzer 3.6-24 {mu}m color. These trends may be due to variations in the spatial density of young stars, the stellar age, the ratio of young to old stars, the initial mass function, and/or the efficiency of stellar feedback. Galaxies with low SFR (<1 M_{sun}_/yr) and high K band luminosities may have an excess of hot gas relative to the relation for higher SFR galaxies, while galaxies with low K band luminosities (and therefore low stellar masses) may have a deficiency in hot gas, but our sample is not large enough for strong statistical significance.
- 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.
- 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.
