- ID:
- ivo://CDS.VizieR/J/AJ/130/1763
- Title:
- 11.7{mu}m point sources in Orion
- Short Name:
- J/AJ/130/1763
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new 11.7{mu}m mosaic image of the inner Orion Nebula obtained with the T-ReCS instrument on Gemini South. The map covers 2.7'x1.6', with a diffraction-limited spatial resolution of 0.35"; it includes the BN/KL region, the Trapezium, and OMC-1 South. Excluding BN/KL, we detect 91 thermal-IR point sources, with 27 known proplyds and over 30 "naked" stars showing no extended structure in Hubble Space Telescope (HST) images.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/644/A27
- Title:
- Musca APEX 12CO(2-1), 13CO(2-1) and C18O(2-1) data
- Short Name:
- J/A+A/644/A27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Dense molecular filaments are ubiquituous in the interstellar medium, yet their internal physical conditions and the role of gravity, turbulence, the magnetic field, radiation, and the ambient cloud during their evolution remain debated. We study the kinematics and physical conditions in the Musca filament, the ambient cloud, and the Chamaeleon-Musca complex to constrain the physics of filament formation. We produced CO(2-1) isotopologue maps with the APEX telescope that cut through the Musca filament. We further study a NANTEN2 ^12^CO(1-6>0) map of the full Musca cloud, HI emission of the Chamaeleon-Musca complex, a Planck polarisation map, line radiative tranfer models, Gaia data, and synthetic observations from filament formation simulations. The Musca cloud, with a size of ~3-6pc, contains multiple velocity components. Radiative transfer modelling of the CO emission indicates that the Musca filament consists of a cold (~10K), dense (n_H2_~10^4^cm^-3^) crest, which is best described with a cylindrical geometry. Connected to the crest, a separate gas component at T~15K and n_H2_~10^3^cm^-3^ is found, the so-called strands. The velocity-coherent filament crest has an organised transverse velocity gradient that is linked to the kinematics of the nearby ambient cloud. This velocity gradient has an angle >=30{deg} with respect to the local magnetic field orientation derived from Planck, and the magnitude of the velocity gradient is similar to the transonic linewidth of the filament crest. Studying the large scale kinematics, we find coherence of the asymmetric kinematics from the 50pc HI cloud down to the Musca filament. We also report a strong [C^18^O]/[^13^CO] abundance drop by an order of magnitude from the filament crest to the strands over a distance <0.2pc in a weak ambient far-ultraviolet (FUV) field. The dense Musca filament crest is a long-lived (several crossing times), dynamic structure that can form stars in the near future because of continuous mass accretion replenishing the filament. This mass accretion on the filament appears to be triggered by a HI cloud-cloud collision, which bends the magnetic field around dense filaments. This bending of the magnetic field is then responsible for the observed asymmetric accretion scenario of the Musca filament, which is, for instance, seen as a V-shape in the position-velocity (PV) diagram.
- ID:
- ivo://CDS.VizieR/J/A+A/641/A17
- Title:
- Musca APEX 12CO(2-1), 12CO(3-2) & 12CO(4-3) data
- Short Name:
- J/A+A/641/A17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations with the Herschel Space Telescope have established that most star forming gas is organised in filaments, a finding that is supported by numerical simulations of the supersonic interstellar medium (ISM) where dense filamentary structures are ubiquitous. We aim to understand the formation of these dense structures by performing observations covering the ^12^CO(4-3), ^12^CO(3-2), and various CO(2-1) isotopologue lines of the Musca filament, using the APEX telescope. The observed CO intensities and line ratios cannot be explained by PDR (photodissociation region) emission because of the low ambient far-UV field that is strongly constrained by the non-detections of the [CII] line at 158um and the [OI] line at 63um, observed with the upGREAT receiver on SOFIA, as well as a weak [CI] 609um line detected with APEX. We propose that the observations are consistent with a scenario in which shock excitation gives rise to warm and dense gas close to the highest column density regions in the Musca filament. Using shock models, we find that the CO observations can be consistent with excitation by J-type low-velocity shocks. A qualitative comparison of the observed CO spectra with synthetic observations of dynamic filament formation simulations shows a good agreement with the signature of a filament accretion shock that forms a cold and dense filament from a converging flow. The Musca filament is thus found to be dense molecular post-shock gas. Filament accretion shocks that dissipate the supersonic kinetic energy of converging flows in the ISM may thus play a prominent role in the evolution of cold and dense filamentary structures.
- ID:
- ivo://CDS.VizieR/J/A+A/510/A54
- Title:
- NaI and CaII interstellar absorption
- Short Name:
- J/A+A/510/A54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new high resolution (R>50000) absorption measurements of the NaI doublet (5889-5895{AA}) along 482 nearby sight-lines, in addition to 807 new measurements of the CaII K (3933{AA}) absorption line. We have combined these new data with previously reported measurements to produce a catalog of absorptions towards a total of 1857 early-type stars located within 800pc of the Sun. Using these data we have determined the approximate 3-dimensional spatial distribution of neutral and partly ionized interstellar gas density within a distance-cube of 300pc from the Sun.
595. NaI in Local Bubble
- ID:
- ivo://CDS.VizieR/J/A+A/346/785
- Title:
- NaI in Local Bubble
- Short Name:
- J/A+A/346/785
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present preliminary results form a long-term program of mapping the neutral absorption characteristics of the local interstellar medium, taking advantage of Hipparcos stellar distances. Equivalent width of the NaI D-line doublet at 5890{AA} are presented for the lines-of-sight towards some 143 new target stars lying within 300pc of the Sun.
- ID:
- ivo://CDS.VizieR/J/A+A/585/A117
- Title:
- N131 bubble CO integrated intensity maps
- Short Name:
- J/A+A/585/A117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- OB-type stars have strong ionizing radiation and drive energetic winds. The ultraviolet radiation from ionizing stars may heat dust and ionize gas to sweep up an expanding bubble shell. This shell may be the result of feedback leading to a new generation of stars. N131 is an infrared dust bubble residing in a molecular filament. We study the formation and fragmentation of this bubble with multiwavelength dust and gas observations. Towards the bubble N131, we analysed archival multiwavelength observations including 3.6, 4.5, 5.8, 8.0, 24, 70, 160, 250, 350, 500um, 1.1mm, and 21cm. In addition, we performed new observations of CO (2-1), CO (1-0), and ^13^CO (1-0) with the IRAM 30m telescope.
- ID:
- ivo://CDS.VizieR/J/A+A/579/A130
- Title:
- Near-IR BN/KL outflow images
- Short Name:
- J/A+A/579/A130
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Adaptive optics images are used to test the hypothesis that the explosive BN/KL outflow from the Orion OMC1 cloud core was powered by the dynamical decay of a non-hierarchical system of massive stars. Narrow-band H_2_, [FeII], and broad-band Ks obtained with the Gemini South multi-conjugate adaptive optics (AO) system GeMS and near-infrared imager GSAOI are presented. The images reach resolutions of 0.08 to 0.10" to the 0.07" diffraction limit of the 8-meter telescope at 2.12um. Comparison with previous AO-assisted observations of sub-fields and other ground-based observations enable measurements of proper motions and the investigation of morphological changes in H_2_ and [FeII] features with unprecedented precision. The images are compared with numerical simulations of compact, high-density clumps moving ~10^3^ times their own diameter through a lower density medium at Mach 10^3^.
- ID:
- ivo://CDS.VizieR/J/A+A/591/A74
- Title:
- Nebular emission lines towards NGC3372 center
- Short Name:
- J/A+A/591/A74
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations from the Gaia-ESO Survey in the lines of H{alpha}, [NII], [SII], and He I of nebular emission in the central part of the Carina nebula. We investigate the properties of the two already known kinematic components (approaching and receding), which account for the bulk of emission. Moreover, we investigate the features of the much less known low-intensity high-velocity (absolute RV>50km/s) gas emission. We show that gas giving rise to H{alpha} and HeI emission is dynamically well correlated with but not identical to gas seen through forbidden-line emission. Gas temperatures are derived from line-width ratios, and densities from [SII] doublet ratios. The spatial variation of N ionization is also studied, and found to differ between the approaching and receding components. The main result is that the bulk of the emission lines in the central part of Carina arise from several distinct shell-like expanding regions, the most evident found around {eta} Car, the Trumpler 14 core, and the star WR25. These "shells" are non-spherical and show distortions probably caused by collisions with other shells or colder, higher-density gas. Some of them are also partially obscured by foreground dust lanes, while very little dust is found in their interior. Preferential directions, parallel to the dark dust lanes, are found in the shell geometries and physical properties, probably related to strong density gradients in the studied region. We also find evidence that the ionizing flux emerging from {eta} Car and the surrounding Homunculus nebula varies with polar angle. The high-velocity components in the wings of H{alpha} are found to arise from expanding dust reflecting the {eta} Car spectrum.
- ID:
- ivo://CDS.VizieR/J/A+A/542/A110
- Title:
- Neutral gas in the Milky Way halo
- Short Name:
- J/A+A/542/A110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an absorption-selected survey of CaII and NaI features located in the halo of the Milky Way using QSO absorption spectroscopy. We made use of the ESO data archive and retrieved all publically available absorption-line data for low- and high-redshift QSOs observed with the Ultraviolet and Visual Echelle Spectrograph (UVES) on the VLT. This enormous data archive (Spectral Quasar Absorption Database, SQUAD; PI: M.T. Murphy) provides high-quality spectral data for ~400 quasars and active galactic nuclei (AGN). Most of these spectra were taken in the UVES standard configuration using the 1" slit, providing a spectral resolution of R~45000 (corresponding to a velocity resolution of ~6.6km/sFWHM). The spectral coverage as well as the signal-to-noise ratio (S/N) varies substantially among the spectra, reflecting the various scientific goals of the original proposals. For several of the sight lines we performed deep (brightness temperature limit, Tb_lim_~30mK, angular resolution: 9' FWHM, spectral resolution: 0.5km/s FWHM) follow-up radio observations using the Effelsberg 100-m telescope to search for HI emission. Furthermore for a large fraction of the sight lines we obtained HI data from the new Galactic All-Sky survey (GASS, Tb_lim_~60mK, angular resolution: 15.6' FWHM, spectral resolution: 0.8km/s FWHM) and the Effelsberg-Bonn HI survey (EBHIS, Tb_lim_~90mK, angular resolution: 10.5' FWHM, spectral resolution: 1.2km/s FWHM). All HI data were corrected for stray radiation using software by P. Kalberla.
- ID:
- ivo://CDS.VizieR/J/A+A/644/A133
- Title:
- New APEX-SEPIA660 observations in OMC-1
- Short Name:
- J/A+A/644/A133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The star-formation rates and stellar densities found in young massive clusters suggest that these stellar systems originate from gas at densities of n(H_2_)>10^6^cm^-3^. Until today, however, the physical characterization of this ultra high density material remains largely unconstrained in observations. We investigate the density properties of the star-forming gas in the OMC-1 region located in the vicinity of the Orion Nebula Cluster (ONC). Methods. We mapped the molecular emission at 652GHz in OMC-1 as part of the APEX-SEPIA660 Early Science. We detect bright and extended N_2_H^+^ (J=7-6) line emission along the entire OMC-1 region. Comparisons with previous ALMA data of the (J=1-0) transition and radiative transfer models indicate that the line intensities observed in this N_2_H^+^ (7-6) line are produced by large mass reservoirs of gas at densities n(H_2_)>10^7^cm^-3^. The first detection of this N_2_H^+^ (7-6) line at parsec-scales demonstrates the extreme density conditions of the star-forming gas in young massive clusters such as the ONC. Our results highlight the unique combination of sensitivity and mapping capabilities of the new SEPIA660 receiver for the study of the ISM properties at high frequencies.
