- 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.
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- 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.
- ID:
- ivo://CDS.VizieR/J/ApJS/206/9
- Title:
- New EGOs from Spitzer GLIMPSE II survey. I.
- Short Name:
- J/ApJS/206/9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have produced a catalog containing 98 newly identified massive young stellar object (MYSO) candidates associated with ongoing outflows (known as extended green objects, or EGOs). These have been identified from the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) II data set and our new identifications increase the number of known EGOs to ~400 in our Galaxy, adding to the ~300 previously identified EGOs reported by Cyganowski et al. (2008, Cat. J/AJ/136/2391) from the GLIMPSE I survey. The high detection rate (~70%) of 95 GHz class I methanol masers achieved in a survey toward 57 of these new EGOs with the Mopra 22m radio telescope demonstrates that the new EGOs are associated with outflows. Investigations of the mid-infrared properties and physical associations with other star formation tracers (e.g., infrared dark clouds, class I and II methanol masers, and millimeter Bolocam Galactic Plane Survey sources) reveal that the newly identified EGOs are very similar in nature to those in the sample of Cyganowski et al. All of the observational evidence supports the hypothesis that EGOs correspond to MYSOs at the earliest evolutionary stage, with ongoing outflow activity, and active rapid accretion.
- ID:
- ivo://CDS.VizieR/J/ApJS/206/22
- Title:
- Newly EGOs from GLIMPSE II survey. II. MoC
- Short Name:
- J/ApJS/206/22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have undertaken a survey of molecular lines in the 3mm band toward 57 young stellar objects using the Australia Telescope National Facility Mopra 22m radio telescope. The target sources were young stellar objects with active outflows (extended green objects (EGOs)) newly identified from the GLIMPSE II survey. We observe a high detection rate (50%) of broad line wing emission in the HNC and CS thermal lines, which combined with the high detection rate of class I methanol masers toward these sources (reported in Paper I, Cat. J/ApJS/206/9) further demonstrates that the GLIMPSE II EGOs are associated with outflows. The physical and kinematic characteristics derived from the 3mm molecular lines for these newly identified EGOs are consistent with these sources being massive young stellar objects with ongoing outflow activity and rapid accretion. These findings support our previous investigations of the mid-infrared properties of these sources and their association with other star formation tracers (e.g., infrared dark clouds, methanol masers and millimeter dust sources) presented in Paper I. The high detection rate (64%) of the hot core tracer CH_3_CN reveals that the majority of these new EGOs have evolved to the hot molecular core stage. Comparison of the observed molecular column densities with predictions from hot core chemistry models reveals that the newly identified EGOs from the GLIMPSE II survey are members of the youngest hot core population, with an evolutionary time scale of the order of 10^3^yr.
- ID:
- ivo://CDS.VizieR/J/ApJ/753/27
- Title:
- New point sources in the WMAP 7yr data
- Short Name:
- J/ApJ/753/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have developed a new needlet-based method to detect point sources in cosmic microwave background (CMB) maps and have applied it to the Wilkinson Microwave Anisotropy Probe (WMAP) 7 year data. We use both the individual frequency channels as well as internal templates, the latter being the difference between pairs of frequency channels and hence having the advantage that the CMB component is eliminated. Using the area of the sky outside the Kq85 galactic mask, we detect a total of 2102 point sources at the 5{sigma} level in either the frequency maps or the internal templates. Of these, 1116 are detected either at 5{sigma} directly in the frequency channels or at 5{sigma} in the internal templates and >=3{sigma} at the corresponding position in the frequency channels. Of the 1116 sources, 603 are detections that have not been reported so far in WMAP data. We have made a catalog of these sources available with position and flux estimated in the WMAP channels where they are seen. In total, we identified 1029 of the 1116 sources with counterparts at 5GHz and 69 at other frequencies.
- ID:
- ivo://CDS.VizieR/J/A+A/632/A33
- Title:
- NGC 613 ALMA datacubes
- Short Name:
- J/A+A/632/A33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report ALMA observations of CO(3-2) emission in the Seyfert/nuclear starburst galaxy NGC613, at a spatial resolution of 17pc, as part of our NUclei of GAlaxies (NUGA) sample. Our aim is to investigate the morphology and dynamics of the gas inside the central kiloparsec, and to probe nuclear fueling and feedback phenomena. The morphology of CO(3-2) line emission reveals a two arm trailing nuclear spiral at r<~100pc and a circumnuclear ring at a radius of ~350pc that is coincident with the star-forming ring seen in the optical images. Also, we find evidence for a filamentary structure connecting the ring and the nuclear spiral. The ring reveals two breaks into two winding spiral arms corresponding to the dust lanes in the optical images. The molecular gas in the galaxy disk is in a remarkably regular rotation, however the kinematics in the nuclear region are very skewed. The nuclear spectrum of CO and dense gas tracers HCN(4-3), HCO^+^(4-3), and CS(7-6) show broad wings up to 300km/s, associated with a molecular outflow emanating from the nucleus (r~25pc). We derive a molecular outflow mass M_out_=2x10^6^M_[sun}_ and a mass outflow rate of dM_out_/dt=27M_[sun}/yr. The molecular outflow energetics exceed the values predicted by AGN feedback models: the kinetic power of the outflow corresponds to P_K,out_=20%L_AGN_ and the momentum rate is dM_out_/dt*v~400L_AGN_/c. The outflow is mainly boosted by the AGN through entrainment by the radio jet, but given the weak nuclear activity of NGC613, we might be witnessing a fossil outflow resulting from a previously strong AGN that has now faded. Furthermore, the nuclear trailing spiral observed in CO emission is inside the inner Lindblad resonance ring of the bar. We compute the gravitational torques exerted in the gas to estimate the efficiency of the angular momentum exchange. The gravity torques are negative from 25 to 100pc and the gas loses its angular momentum in a rotation period, providing evidence for a highly efficient inflow towards the center. This phenomenon shows that the massive central black hole has significant dynamical influence on the gas, triggering the inflowing of molecular gas to feed the black hole.
- ID:
- ivo://CDS.VizieR/J/A+A/635/A2
- Title:
- NGC6334 ALMA 87.6GHz continuum emission map
- Short Name:
- J/A+A/635/A2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim to characterise certain physical properties of high-mass star-forming sites in the NGC6334 molecular cloud, such as the core mass function (CMF), spatial distribution of cores, and mass segregation. We used the Atacama Large Millimetre/sub-millimetre Array (ALMA) to image the embedded clusters NGC6334-I and NGC6334-I(N) in the continuum emission at 87.6GHz. We achieved a spatial resolution of 1300au, enough to resolve different compact cores and fragments, and to study the properties of the clusters. We detected 142 compact sources distributed over the whole surveyed area. The ALMA compact sources are clustered in different regions. We used different machine-learning algorithms to identify four main clusters: NGC6334-I, NGC6334-I(N), NGC6334-I(NW), and NGC6334-E. The typical separations between cluster members range from 4000au to 12000au. These separations, together with the core masses (0.1-100M_{sun}_), are in agreement with the fragmentation being controlled by turbulence at scales of 0.1pc. We find that the CMFs show an apparent excess of high-mass cores compared to the stellar Initial Mass Function. We evaluated the effects of temperature and unresolved multiplicity on the derived slope of the CMF. Based on this, we conclude that the excess of high-mass cores might be spurious and due to inaccurate temperature determinations and/or resolution limitations. We searched for evidence of mass segregation in the clusters and we find that clusters NGC6334-I and NGC6334-I(N) show hints of segregation with the most massive cores located in the centre of the clusters. We searched for correlations between the physical properties of the four embedded clusters and their evolutionary stage (based on the presence of Hii regions and infrared sources). NGC6334-E appears as the most evolved cluster, already harboring a well-developed Hii region. NGC6334-I is the second-most evolved cluster with an ultra-compact Hii region. NGC6334-I(N) contains the largest population of dust cores distributed in two filamentary structures and no dominant Hii region. Finally, NGC6334-I(NW) is a cluster of mainly low-mass dust cores with no clear signs of massive cores or Hii regions.We find a larger separation between cluster members in the more evolved clusters favoring the role of gas expulsion and stellar ejection with evolution. The mass segregation, seen in the NGC6334-I and NGC6334-I(N) clusters, suggests a primordial origin for NGC6334-I(N). In contrast, the segregation in NGC6334-I might be due to dynamical effects. Finally, the lack of massive cores in the most evolved cluster suggests that the gas reservoir is already exhausted, while the less evolved clusters still have a large gas reservoir along with the presence of massive cores. In general, the fragmentation process of NGC6334 at large scales (from filament to clump, i.e. at about 1pc) is likely governed by turbulent pressure, while at smaller scales (scale of cores and sub-fragments, i.e. a few hundred au) thermal pressure starts to be more significant.
