- ID:
- ivo://CDS.VizieR/J/A+A/406/L47
- Title:
- 17OH spin-rotation transition frequencies
- Short Name:
- J/A+A/406/L47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The frequencies and line strengths of the ^2^{Pi}_3/2_ J=5/2-3/2 rotational transition of ^17^OH have been calculated from an analysis of its far-infrared laser magnetic resonance spectrum. These results have been used to make the first detection of a pure rotational transition of ^17^OH in the ISM. Two resolved components of this transition appear in absorption towards the giant molecular cloud Sagittarius B2, which was observed at a spectral resolution of 33km/s with the Fabry-Perot mode of the ISO Long Wavelength Spectrometer. The corresponding transition of ^18^OH was also observed and its line shape was modelled using HI measurements. The ^18^O/^17^O ratio of 3.5 was then used to compare this with the observed ^17^OH line shape.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/549/155
- Title:
- [OIII] emission in a sample of AGNs
- Short Name:
- J/ApJ/549/155
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The emission-line flux ratio of [OIII]4363/[OIII]5007 (R_OIII_) is a useful diagnostic for the ionization mechanism and physical properties of emission-line regions in active galactic nuclei (AGNs). However, it is known that simple photoionization models underpredict the [OIII]4363 intensity, being inconsistent with observations. In this paper we report on several pieces of evidence that a large fraction of the [OIII]4363 emission arises from the dense gas obscured by putative tori: (1) the visibility of high-R_OIII_ regions is correlated to that of broad-line regions, (2) higher R_OIII_ objects show hotter mid-infrared colors, (3) higher R_OIII_ objects show stronger highly ionized emission lines such as [FeVII] 6087 and [FeX]6374, and (4) higher R_OIII_ objects have broader line width of [OIII]4363 normalized by that of [OIII]5007.
- ID:
- ivo://CDS.VizieR/J/A+A/596/A26
- Title:
- OMC-2 FIR 3 and FIR 4 [OI] maps
- Short Name:
- J/A+A/596/A26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first detection of a jet in the far-IR [OI] lines from an intermediate mass protostar. We have carried out a Herschel/PACS spectral mapping study in the [OI] lines of OMC-2 FIR 3 and FIR 4, two of the most luminous protostars in Orion outside of the Orion Nebula. The spatial morphology of the fine structure line emission reveals the presence of an extended photodissociation region (PDR) and a narrow, but intense jet emission connecting the two protostars. The jet seen in [OI] emission is spatially aligned with the Spitzer/IRAC 4.5um jet and the CO (6-5) molecular outflow centered on FIR 3. The mass loss rate derived from the total [OI] 63um line luminosity of the jet is 7.7*10^-6^M_{sun}_/yr, which is more than an order of magnitude higher than that measured for typical low mass class 0 protostars. The implied accretion luminosity is significantly higher than the observed bolometric luminosity of FIR 4, indicating that the [OI] jet is unlikely to be associated with FIR 4. We argue that the peak line emission seen toward FIR 4 originates in the terminal shock produced by the jet driven by FIR 3. The higher mass loss rate that we find for FIR 3 is consistent with the idea that intermediate mass protostars drive more powerful jets than their low-mass counterparts. Our results also call into question the nature of FIR 4.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A136
- Title:
- OMC-2 FIR4 fits images
- Short Name:
- J/A+A/657/A136
- Date:
- 21 Mar 2022 09:38:35
- Publisher:
- CDS
- Description:
- Isotopic fractionation is an important tool for investigating the chemical history of our Solar System. In particular, the isotopic fraction of nitrogen (^14^N/^15^N) is lower in comets and other pristine Solar System bodies with respect to the value measured for the protosolar nebula, suggesting a local chemical enrichment of ^15^N during the formation of the Solar System. Therefore, interferometric studies of nitrogen fractionation in Solar System precursors are needed for us to obtain clues about our astrochemical origins. In this work we have investigated the variation in the ^14^N/^15^N ratio in one of the closest analogues of the environment in which the Solar System was born: the protocluster OMC-2 FIR4. We present the first comparison at high angular resolution between HCN and N_2_H^+^ using interferometric data. We analysed observations of the HCN isotopologues H^13^CN and HC^15^N in the OMC-2 FIR4 protocluster. Specifically, we observed the transitions H^13^CN (1-0) and HC^15^N (1-0) with the NOrthern Extended Millimeter Array (NOEMA) within the context of the IRAM Seeds Of Life In Space (SOLIS) Large Program. We combined our results with analysis of archival data obtained with the Atacama Large Millimeter Array (ALMA) of N_2_H^+^ and its ^15^N isotopologues. Our results show a small regional variation in the ^14^N/^15^N ratio for HCN, from ~250 to 500. The ratios in the central regions of FIR4, where the candidate protostars are located, are largely consistent with one another and within that range (~300). They also show little variation from the part of the protocluster known to harbour a high cosmic-ray ionisation rate to the portion with a lower rate. We also found a small variation in the ^14^N/^15^N ratio of N_2_H^+^ across different regions, from ~200 to ~400. These results suggest that local changes in the physical parameters occurring on the small linear scales probed by our observations in the protocluster do not seem to affect the ^14^N/^15^N ratio in either HCN or N_2_H^+^ and hence that this is independent of the molecule used. Moreover, the high level of irradiation due to cosmic rays does not affect the N fractionation either.
- ID:
- ivo://CDS.VizieR/J/AJ/135/1395
- Title:
- omega Cen Spitzer photometry
- Short Name:
- J/AJ/135/1395
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a Spitzer Space Telescope imaging survey of the most massive Galactic globular cluster, {omega} Centauri, and investigate stellar mass loss at low metallicity and the intracluster medium (ICM). The survey covers approximately 3.2x the cluster half-mass radius at 3.6, 4.5, 5.8, 8, and 24um, resulting in a catalog of over 40000 point sources in the cluster.
- ID:
- ivo://CDS.VizieR/J/MNRAS/414/702
- Title:
- Optical classification of southern ULIRGs
- Short Name:
- J/MNRAS/414/702
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the optical spectral properties of 115 ultraluminous infrared galaxies (ULIRGs) in the southern sky. Using the optical spectra obtained at the Cerro Tololo Inter-American Observatory (CTIO) 4m telescope and provided by the Two-degree Field (2dF) Galaxy Redshift Survey and the Six-degree Field (6dF) Galaxy Survey, we measure emission linewidths and fluxes for spectral classification.
- ID:
- ivo://CDS.VizieR/VI/112
- Title:
- Optical Imaging of 57 spiral galaxies
- Short Name:
- VI/112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical observations of a sample of 57 spiral galaxies and describe the procedures followed to reduce the data. We have obtained images in the optical B and I broad bands, as well as in H{alpha}, with moderate spatial resolution and across wide enough fields to image the complete disks of the galaxies. In addition, we observed 55 of our sample galaxies in the R and eight in the V band, and imaged a subset through a dedicated narrow continuum filter for the H{alpha} line. We describe the data reduction procedures we developed in the course of this work to register, combine and photometrically calibrate each set of images for an individual galaxy. We describe in some detail the procedure used to subtract the continuum emission from our H{alpha} images. In companion papers, we describe near-infrared imaging of the galaxy sample, and present analyses of disk scale lengths, and of properties of bars, rings, and HII regions in the sample galaxies. The images described here will be made available for use by other researchers through the CDS.
- ID:
- ivo://CDS.VizieR/J/MNRAS/472/334
- Title:
- Optical/MIR properties of Type 1 AGNs
- Short Name:
- J/MNRAS/472/334
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigated the connection between the mid-infrared (MIR) and optical spectral characteristics in a sample of 82 Type 1 active galactic nuclei (AGNs), observed with Infrared Spectrometer on Spitzer (IRS) and Sloan Digital Sky Survey (SDSS, DR12). We found several interesting correlations between optical and MIR spectral properties: (i) as starburst significators in MIR increase, the equivalent widths (EWs) of optical lines H{beta}NLR and FeII, increase as well; (ii) as MIR spectral index increases, EW([OIII]) decreases, while fractional contribution of AGN (RAGN) is not connected with EW([OIII]); (iii) The log([OIII]5007/H{beta}NLR) ratio is weakly related to the fractional contribution of polycyclic aromatic hydrocarbons (RPAHs). We compare the two different MIR and optical diagnostics for starburst contribution to the overall radiation (RPAH and Baldwin, Philips & Terlevich diagram, respectively). The significant differences between optical and MIR starburst diagnostics were found. The starburst influence to observed correlations between optical and MIR parameters is discussed.
- ID:
- ivo://CDS.VizieR/J/A+A/431/779
- Title:
- Optical/near-IR atlas of OH/IR stars
- Short Name:
- J/A+A/431/779
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present optical and near-infrared finding charts, accurate astrometry (~1") and single-epoch near-infrared photometry for 371 IRAS sources, 96% of those included in the so-called "Arecibo sample of OH/IR stars" (Eder et al., 1988ApJS...66..183E; Lewis et al., 1990ApJ...362..634L; Chengalur et al., 1993, Cat. <J/ApJS/89/189>). The main photometric properties of the stars in the sample are presented and discussed as well as the problems found during the process of identification of the optical/near-infrared counterparts. In addition, we also identify suitable reference stars in each field to be used for differential photometry purposes in the future.
- ID:
- ivo://CDS.VizieR/J/A+A/566/A60
- Title:
- Optical-NIR catalog of AKARI NEP Deep Field
- Short Name:
- J/A+A/566/A60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an 8-band (u*, g', r', i', z', Y, J, Ks) optical to near-infrared deep photometric catalogue based on the observations made with MegaCam and WIRCam at CFHT, and compute photometric redshifts, zph in the North Ecliptic Pole (NEP) region, where AKARI infrared satellite carried out deep survey at near to mid infrared wavelength. We designed the catalogue to include sources detected in z' band with counterparts in at least one of the other bands, and found 85797 sources in the NEP field. Comparing with galaxy spectroscopic redshifts, photometric redshift dispersion {sigma}({Delta}z/(1+z)) is 0.032 and catastrophic failure rate {Delta}z/(1+z)>0.15 is 5.8% at z<1. Our redshifts are highly accurate with z'<22 at zph<2.5 and for fainter sources with z'<24 at z<1.
