- ID:
- ivo://CDS.VizieR/J/A+A/642/A152
- Title:
- HD101584 VLTI/PIONIER images
- Short Name:
- J/A+A/642/A152
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The observed orbital characteristics of post-asymptotic giant branch (post-AGB) and post-red giant branch (post-RGB) binaries are not understood. We suspect that the missing ingredients to explain them probably lie in the continuous interaction of the central binary with its circumstellar environment. We aim at studying the circumbinary material in these complex systems by investigating the connection between the innermost and large-scale structures. We perform high-angular resolution observations in the near-infrared continuum of HD101584, which has a complex structure as seen at millimeter wavelengths with a disk-like morphology and a bipolar outflow due to an episode of strong binary interaction. To account for the complexity of the target we first perform an image reconstruction and use this result to fit a geometrical model to extract the morphological and thermal features of the environment. The image reveals an unexpected double-ring structure. We interpret the inner ring to be produced by emission from dust located in the plane of the disk and the outer ring to be produced by emission from dust that is located 1.6[D/1kpc] au above the disk plane. The inner ring diameter (3.94[D/1kpc] au), and temperature (T=1540+/-10K) are compatible with the dust sublimation front of the disk. The origin of the out-of-plane ring (with a diameter of 7.39[D/1kpc] au and a temperature of 1014+/-10K) could be due to episodic ejection or a dust condensation front in the outflow. The observed outer ring is possibly linked with the blue-shifted side of the large scale outflow seen by ALMA and is tracing its launching location to the central star. Such observations give morphological constraints on the ejection mechanism. Additional observations are needed to constrain the origin of the out-of-plane structure.
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- ID:
- ivo://CDS.VizieR/J/A+A/559/A111
- Title:
- 89 Her interferometric study
- Short Name:
- J/A+A/559/A111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Binary post-asymptotic giant branch (post-AGB) stars are interesting laboratories to study both the evolution of binaries as well as the structure of circumstellar disks. A multiwavelength high angular resolution study of the prototypical object 89 Herculis is performed with the aim of identifying and locating the different emission components seen in the spectral energy distribution. A large interferometric data set, collected over the past decade and covering optical and near-infrared wavelengths, is analyzed in combination with the spectral energy distribution and flux-calibrated optical spectra. In this first paper only simple geometric models are applied to fit the interferometric data. Combining the interferometric constraints with the photometry and the optical spectra, we re-assess the energy budget of the post-AGB star and its circumstellar environment.
- ID:
- ivo://CDS.VizieR/J/A+A/568/L5
- Title:
- HH 212 CO, CS and 850um ALMA images
- Short Name:
- J/A+A/568/L5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We wish to exploit the unmatched combination of high angular resolution, high sensitivity, high-imaging fidelity, and spectral coverage provided by ALMA to shed light on the complex kinematics of the innermost central regions of HH212 protostellar system. We mapped the inner 10" (4500AU) of the HH212 system at ~0.5" resolution in several molecular tracers and in the 850um dust continuum using the ALMA interferometer in band 7 in the extended configuration of the Early Science Cycle 0 operations. Within a single ALMA spectral set-up, we simultaneously identify all the crucial ingredients known to be involved in the star formation recipe: (i) the fast, collimated bipolar SiO jet driven by the protostar; (ii) the large-scale swept-up CO outflow; (iii) the flattened rotating and infalling envelope, with bipolar cavities carved by the outflow (in C^17^O(3-2)); and (iv) a rotating wide-angle flow that fills the cavities and surrounds the axial jet (in C^34^S(7-6)). In addition, the compact high-velocity C^17^O emission (+/-1.9-3.5km/s from systemic) shows a velocity gradient along the equatorial plane consistent with a rotating disk of ~0.2"=90AU around a ~0.3+/-0.1M_{sun}_ source. The rotating disk is possibly Keplerian. HH212 is the third Class 0 protostar with possible signatures of a Keplerian disk of radius >=30AU. The warped geometry in our CS data suggests that this large Keplerian disk might result from misaligned magnetic and rotation axes during the collapse phase. The wide-angle CS flow suggests that disk winds may be present in this source.
- ID:
- ivo://CDS.VizieR/J/A+A/582/A18
- Title:
- HI data cubes of 4 edge-on spiral galaxies
- Short Name:
- J/A+A/582/A18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Edge-on galaxies can offer important insight into galaxy evolution because they are the only systems where the distribution of the different components can be studied both radially and vertically. The HEROES project was designed to investigate the interplay between the gas, dust, stars, and dark matter (DM) in a sample of 7 massive edge-on spiral galaxies. In this second HEROES paper, we present an analysis of the atomic gas content of 6 out of 7 galaxies in our sample. The remaining galaxy was recently analysed according to the same strategy. The primary aim of this work is to constrain the surface density distribution, the rotation curve, and the geometry of the gas disks in a homogeneous way. In addition we identify peculiar features and signs of recent interactions. We have constructed detailed tilted-ring models of the atomic gas disks based on new GMRT 21-cm observations of NGC 973 and UGC 4277 and re-reduced archival HI data of NGC 5907, NGC 5529 IC 2531, and NGC 4217. Potential degeneracies between different models were resolved by requiring good agreement with the data in various representations of the data cubes. From our modelling we find that all but one galaxy are warped along the major axis. In addition, we identify warps along the line of sight in three galaxies. A flaring gas layer is required to reproduce the data for only one galaxy, but (moderate) flares cannot be ruled out for the other galaxies either. A coplanar ring-like structure is detected outside the main disk of NGC 4217, which we suggest could be the remnant of a recent minor merger event. We also find evidence of a radial inflow of 15 +/-5km/s in the disk of NGC 5529, which might be related to the ongoing interaction with two nearby companions. For NGC 5907 the extended, asymmetric, and strongly warped outer regions of the HI disk also suggest a recent interaction. In contrast, the inner disks of these three galaxies (NGC 4217, NGC 5529, and NGC 5907) show regular behaviour and seem largely unaffected by the interactions. Our models further support earlier claims of prominent spiral arms in the disks of IC 2531 and NGC 5529. Finally, we detect a dwarf companion galaxy at a projected distance of 36 kpc from the centre of NGC 973.
- ID:
- ivo://CDS.VizieR/J/A+A/481/553
- Title:
- High-precision angular diameter of V3879 Sgr
- Short Name:
- J/A+A/481/553
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our goal is to demonstrate the potential of the interferometric AMBER instrument linked with the Very Large Telescope Interferometer (VLTI) fringe-tracking facility FINITO to derive high-precision stellar diameters. We use commissioning data obtained on the bright single star V3879 Sgr. Locking the interferometric fringes with FINITO allows us to record very low contrast fringes on the AMBER camera. By fitting the amplitude of these fringes, we measure the diameter of the target in three directions simultaneously with an accuracy of 25micro-arcseconds. We showed that V3879 Sgr has a round photosphere down to a sub-percent level. We quickly reached this level of accuracy because the technique used is independent from absolute calibration (at least for baselines that fully span the visibility null). We briefly discuss the potential biases found at this level of precision.
- ID:
- ivo://CDS.VizieR/J/A+A/469/207
- Title:
- High-resolution images in Cep-A HW2 region
- Short Name:
- J/A+A/469/207
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Due to its relatively small distance (725pc), the Cepheus A East star-forming region is an ideal laboratory to study massive star formation processes. Based on its morphology, it has been suggested that the flattened molecular gas distribution around the YSO HW2 may be a 350-AU-radius massive protostellar disk. The goal of our work is to ascertain the nature of this structure. We have employed the Plateau de Bure Interferometer to acquire (sub-)arcsecond-resolution imaging of high-density and shock tracers, such as methyl cyanide (CH3CN) and silicon monoxide (SiO), towards the HW2 position. On the 1" scale, the flattened distribution of molecular gas around HW2 appears to be due to the projected superposition, on the plane of the sky, of at least three protostellar objects, of which at least one is powering a molecular outflow at a small angle with respect to the line of sight. The presence of a protostellar disk around HW2 is not ruled out.
- ID:
- ivo://CDS.VizieR/J/A+A/493/1043
- Title:
- High spatial resolution observations of HM Sge
- Short Name:
- J/A+A/493/1043
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high spatial resolution observations of the close circumstellar environment of the symbiotic system HM Sagittae obtained with the Very Large Telescope Interferometer (VLTI) of ESO's Paranal Observatory and MIDI, the MID-infrared Interferometric recombiner. MIDI combines the light of two telescopes and provides spectrally resolved visibilities in the N band atmospheric window. The observations of HM Sge were conducted with the VLT Auxiliary Telescopes (ATs) A0, D0, G1 and H0, providing projected baselines in the range of 64 to 89 meters oriented from PA=72 to 127{deg}. The ATs observations were made during the nights of April 04, May 08/10/16, and July 30. All the observations were made under good atmospheric conditions (average seeing ~0.62") with the worst seeing (~1.05") during the night of July 30 2007. The files includes all visibility and differential phase data recorded from these observations as well as all the characteristics concerning the observations. The log of the observations is shown in the third part of table1. The set of data are complementary to the ones corresponding to the first two parts of Table 1 of the paper previously published in Sacuto et al. (2007, Cat. <J/A+A/465/469>)
- ID:
- ivo://CDS.VizieR/J/A+A/465/469
- Title:
- High spatial resolution observations of HM Sge
- Short Name:
- J/A+A/465/469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high spatial resolution observations of the mid-infrared core of the dusty symbiotic system HM Sge obtained with the Very Large Telescope Interferometer (VLTI) of ESO's Paranal Observatory and MIDI, the MID-infrared Interferometric recombiner. MIDI combines the light of two telescopes and provides spectrally resolved visibilities in the N band atmospheric window. The observations of HM Sge were conducted with the VLT Unit Telescopes (UTs) UT2, UT3 and UT4, providing projected baselines in the range of 32-59 meters oriented from PA=42deg to 105deg and the Auxiliary Telescopes (ATs) E0 and G0, providing projected baselines in the range of 13.5-16 meters oriented around PA=75deg. The UTs observations were made during the nights of July 23-24th 2005, May 17th 2006 and June 11th 2006. The ATs observations were made during the nights of May 27th 2006 and June 16th 2006. All the observations were made under good atmospheric conditions (Mean[seeing]~1.01") with the worst seeing (~1.75") during the night of July 23th 2005. The files includes all visibility and differential phase data recorded from these observations as well as all the characteristics concerning the observations. The log of the observations is shown in Table 1 of the paper (table1.dat).
- ID:
- ivo://CDS.VizieR/J/A+A/482/561
- Title:
- High spatial resolution observations of pi^1^ Gru
- Short Name:
- J/A+A/482/561
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high spatial resolution observations of the close circumstellar environment of the semi-regular S-type star pi^1^ Gruis obtained with the Very Large Telescope Interferometer (VLTI) of ESO's Paranal Observatory and MIDI, the MID-infrared Interferometric recombiner. MIDI combines the light of two telescopes and provides spectrally resolved visibilities in the N band atmospheric window. The observations of pi^1^ Gruis were conducted with the VLT Auxiliary Telescopes (ATs) A0, E0, D0 and G0, providing projected baselines in the range of 15 to 64 meters oriented from PA=41 to 102{deg}. The ATs observations were made during the nights of May 21-23-24-25-27 2006, June 19 2006, and August 08 2006. All the observations were made under good atmospheric conditions (average seeing ~0.94") with the worst seeing (~1.51") during the night of May 27 2006. The files includes all visibility and differential phase data recorded from these observations as well as all the characteristics concerning the observations. The log of the observations is shown in Table 1.
- ID:
- ivo://CDS.VizieR/J/A+A/627/A106
- Title:
- HI observations of AT 2018cow
- Short Name:
- J/A+A/627/A106
- Date:
- 23 Mar 2022 16:27:48
- Publisher:
- CDS
- Description:
- Unusual stellar explosions represent an opportunity to learn about both stellar and galaxy evolution. Mapping the atomic gas in host galaxies of such transients can lead to an understanding of the conditions triggering them. We provide resolved atomic gas observations of the host galaxy, CGCG137-068, of the unusual, poorly-understood transient AT2018cow searching for clues to understand its nature. We test whether it is consistent with a recent inflow of atomic gas from the intergalactic medium, as suggested for host galaxies of gamma-ray bursts (GRBs) and some supernovae (SNe). We observed the HI hyperfine structure line of the AT2018cow host with the Giant Metrewave Radio Telescope. There is no unusual atomic gas concentration near the position of AT2018cow. The gas distribution is much more regular than those of GRB/SN hosts. The AT2018cow host has an atomic gas mass lower by 0.24dex than predicted from its star formation rate (SFR) and is at the lower edge of the galaxy main sequence. In the continuum we detected the emission of AT2018cow and of a star-forming region in the north-eastern part of the bar (away from AT2018cow). This region hosts a third of the galaxy's SFR. The absence of atomic gas concentration close to AT2018cow, along with a normal SFR and regular HI velocity field, sets CGCG137-068 apart from GRB/SN hosts studied in HI. The environment of AT2018cow therefore suggests that its progenitor may not have been a massive star. Our findings are consistent with an origin of the transient that does not require a connection between its progenitor and gas concentration or inflow: an exploding low-mass star, a tidal disruption event, a merger of white dwarfs, or a merger between a neutron star and a giant star. We interpret the recently reported atomic gas ring in CGCG137-068 as a result of internal processes connected with gravitational resonances caused by the bar.
