- ID:
- ivo://CDS.VizieR/J/ApJ/921/91
- Title:
- Catastrophic cooling in superwinds. II.
- Short Name:
- J/ApJ/921/91
- Date:
- 15 Nov 2021
- Publisher:
- CDS
- Description:
- Superwinds and superbubbles driven by mechanical feedback from super star clusters (SSCs) are common features in many star-forming galaxies. While the adiabatic fluid model can well describe the dynamics of superwinds, several observations of starburst galaxies revealed the presence of compact regions with suppressed superwinds and strongly radiative cooling, i.e., catastrophic cooling. In the present study, we employ the non-equilibrium atomic chemistry and cooling package MAIHEM, built on the FLASH hydrodynamics code, to generate a grid of models investigating the dependence of cooling modes on the metallicity, SSC outflow parameters, and ambient density. While gas metallicity plays a substantial role, catastrophic cooling is more sensitive to high mass-loading and reduced kinetic heating efficiency. Our hydrodynamic simulations indicate that the presence of a hot superbubble does not necessarily imply an adiabatic outflow, and vice versa. Using CLOUDY photoionization models, we predict UV and optical line emission for both adiabatic and catastrophic cooling outflows, for radiation-bounded and partially density-bounded models. Although the line ratios predicted by our radiation-bounded models agree well with observations of star-forming galaxies, they do not provide diagnostics that unambiguously distinguish the parameter space of catastrophically cooling flows. Comparison with observations suggests the possibility of minor density bounding, non-equilibrium ionization, and/or observational bias toward the central outflow regions.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/551/A32
- Title:
- Catching the radio flare in CTA 102
- Short Name:
- J/A+A/551/A32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Very Long Baseline Interferometry (VLBI) observations can resolve the radio structure of active galactic nuclei (AGN) and provide estimates of the structural and kinematic characteristics on parsec-scales in their jets. The changes in the kinematics of the observed jet features can be used to study the physical conditions in the innermost regions of these sources. We performed multifrequency multiepoch Very Long Baseline Array (VLBA) observations of the blazar CTA102 during its 2006 radio flare, the strongest ever reported for this source. These observations provide an excellent opportunity to investigate the evolution of the physical properties of blazars, especially during these flaring events. We want to study the kinematic changes in the source during the strong radio outburst in April 2006 and test the assumption of a shock-shock interaction. This assumption is based on the analysis and modeling of the single-dish observations of CTA 102 (Paper I, 2011A&A...531A..95F). In this paper we study the kinematics of CTA 102 at several frequencies using VLBI observations. From the modeled jet features we derived estimates for the evolution of the physical parameters, such as the particle density and the magnetic field. Furthermore ,we combined our observations during the 2006 flare with long-term VLBA monitoring of the source at 15 GHz and 43 GHz We cross-identified seven features throughout our entire multifrequency observations and find evidence of two possible recollimation shocks around 0.1mas (deprojected 18pc at a viewing angle of 2.6{deg} and 6.0mas (deprojected 1kpc) from the core. The 43GHz observations reveal a feature ejected at epoch t_ej_=2005.9+/-0.2, which could be connected to the 2006 April radio flare. Furthermore, this feature might be associated with the traveling component involved in the possible shock-shock interaction, which gives rise to the observed double peak structure in the single-dish light curves reported in Paper I, 2011A&A...531A..95F.
- ID:
- ivo://CDS.VizieR/J/A+A/580/A121
- Title:
- CaT/[Fe/H] calibration for Galactic bulge stars
- Short Name:
- J/A+A/580/A121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new calibration of the calcium II triplet equivalent widths versus [Fe/H], constructed upon K giant stars in the Galactic bulge. This calibration will be used to derive iron abundances for the targets of the GIBS survey, and is in general especially well suited for solar and supersolar metallicity giants, which are typical of external massive galaxies. To obtain the calibration, about 150 bulge K giants were observed with the GIRAFFE spectrograph at the VLT with a resolution of R~20000 and at R~6000. In the first case, the spectra allowed us to directly determine the Fe abundances from several unblended Fe lines, deriving what we call here high-resolution [Fe/H] measurements. The low-resolution spectra allowed us to measure equivalent widths of the two strongest lines of the near-infrared calcium II triplet at 8542 and 8662{AA}. By comparing the two measurements, we derived a relation between calcium equivalent widths and [Fe/H] that is linear over the metallicity range probed here, -1<[Fe/H]<+0.7. By adding a small second-order correction based on literature globular cluster data, we derived the unique calibration equation [Fe/H]_CaT_=-3.150+0.432W'+0.006W'^2^, with an rms dispersion of 0.197dex, valid across the whole metallicity range -2.3<[Fe/H]<+0.7.
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/1475
- Title:
- CaT in 903 globular clusters
- Short Name:
- J/MNRAS/426/1475
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Although the colour distribution of globular clusters in massive galaxies is well known to be bimodal, the spectroscopic metallicity distribution has been measured in only a few galaxies. After redefining the calcium triplet index-metallicity relation, we use our relation to derive the metallicity of 903 globular clusters in 11 early-type galaxies. This is the largest sample of spectroscopic globular cluster metallicities yet assembled. We compare these metallicities with those derived from Lick indices finding good agreement. In six of the eight galaxies with sufficient numbers of high-quality spectra we find bimodality in the spectroscopic metallicity distribution. Our results imply that most massive early-type galaxies have bimodal metallicity as well as colour distributions. This bimodality suggests that most massive early-type galaxies experienced two periods of star formation.
- ID:
- ivo://CDS.VizieR/J/ApJ/408/305
- Title:
- Cat of Stellar Lyman-Alpha Fluxes
- Short Name:
- J/ApJ/408/305
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The data file gives the measured Lyman alpha flux or upper limits for 275 stars as derived from IUE spectra. The file is a subset of Table 1 of Landsman and Simon in that when a star had multiple measurements, only the best measurement is included in this table. The spectral types, V and B-V magnitudes in the table are culled from various sources as described in the paper. Most of the measurements are derived from low-dispersion spectra, and those derived from high-dispersion spectra are flagged. Each measurement was assigned a data quality code according to the signal to noise after removal of the diffuse Lyman alpha background emission. -1 - upper limit 1 - good quality 2 - fair quality 3 - poor quality 4 - contains saturated pixels The final column gives the ratio of the Ly alpha flux to the total bolometric flux of the star, determined as described in the paper. A roundoff was applied to the fluxes listed here to give the fluxes listed in Table 1 of Landsman and Simon.
3036. CatWISE2020 Catalog
- ID:
- ivo://irsa.ipac/WISE/Catalog/CatWISE2
- Title:
- CatWISE2020 Catalog
- Short Name:
- CatWISE2
- Date:
- 02 Dec 2020 19:45:36
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The CatWISE2020 catalog contains positions and brightnesses for 1,890,715,640 sources selected from combined WISE and NEOWISE all-sky survey data collected from 2010 to 2018 at 3.4 and 4.6 microns (W1 and W2). CatWISE adapts AllWISE software to measure the sources in co-added images created from six month subsets of these data, each representing one coverage of the inertial sky, or epoch. The catalog includes the measured motion of sources in 12 epochs over the 8 year span of the data.
- ID:
- ivo://irsa.ipac/WISE/Catalog/CatWISEPrelim
- Title:
- CatWISE Preliminary Catalog
- Short Name:
- CatWISEPrelim
- Date:
- 02 Dec 2020 01:51:42
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The CatWISE Preliminary catalog contains positions and brightnesses for 900,849,014 sources selected from combined WISE and NEOWISE all-sky survey data collected from 2010 to 2016 at 3.4 and 4.6 microns (W1 and W2). CatWISE adapts AllWISE software to measure the sources in co-added images created from six month subsets of these data, each representing one coverage of the inertial sky, or epoch. The catalog includes the measured motion of sources in 8 epochs over the 6 year span of the data.
- ID:
- ivo://irsa.ipac/WISE/Catalog/CatWISEPrelimRej
- Title:
- CatWISE Preliminary Reject Table
- Short Name:
- CatWISEPrelimRej
- Date:
- 02 Dec 2020 01:51:42
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The CatWISE Preliminary catalog contains positions and brightnesses for 900,849,014 sources selected from combined WISE and NEOWISE all-sky survey data collected from 2010 to 2016 at 3.4 and 4.6 microns (W1 and W2). CatWISE adapts AllWISE software to measure the sources in co-added images created from six month subsets of these data, each representing one coverage of the inertial sky, or epoch. The catalog includes the measured motion of sources in 8 epochs over the 6 year span of the data.
3039. CatWISE2020 Reject Table
- ID:
- ivo://irsa.ipac/WISE/Catalog/CatWISE2Rej
- Title:
- CatWISE2020 Reject Table
- Short Name:
- CatWISE2Rej
- Date:
- 02 Dec 2020 19:45:36
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The CatWISE2020 Reject Table contains positions and brightnesses for 341,799,385 sources selected from combined WISE and NEOWISE all-sky survey data collected from 2010 to 2018 at 3.4 and 4.6 microns (W1 and W2). CatWISE2020 adapts AllWISE software to measure the sources in co-added images created from six month subsets of these data, each representing one coverage of the inertial sky, or epoch. The catalog includes the measured motion of sources in 12 epochs over the 8 year span of the data.
- ID:
- ivo://CDS.VizieR/J/A+A/569/A7
- Title:
- CB17 dust emission (100-500um), N(H) and T maps
- Short Name:
- J/A+A/569/A7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The initial conditions for the gravitational collapse of molecular cloud cores and the subsequent birth of stars are still not well constrained. The characteristic cold temperatures (~10K) in such regions require observations at sub-millimetre and longer wavelengths. The Herschel Space Observatory and complementary ground-based observations presented in this paper have the unprecedented potential to reveal the structure and kinematics of a prototypical core region at the onset of stellar birth. This paper aims to determine the density, temperature, and velocity structure of the star-forming Bok globule CB 17. This isolated region is known to host (at least) two sources at different evolutionary stages: a dense core, SMM1, and a Class I protostar, IRS. We modeled the cold dust emission maps from 100{mu}m to 1.2mm with both a modified blackbody technique to determine the optical depth-weighted line-of-sight temperature and column density and a ray-tracing technique to determine the core temperature and volume density structure. Furthermore, we analysed the kinematics of CB17 using the high-density gas tracer N_2_H^+