- ID:
- ivo://CDS.VizieR/J/AJ/109/2318
- Title:
- Extragalactic IRAS sources
- Short Name:
- J/AJ/109/2318
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Extragalactic sources detected at lambda=60um were selected from the IRAS Faint Source Catalog, Version 2 (Cat. II/156) by the criterion S(60um)>=S(12um). They were identified by position coincidence with radio sources stronger than 25mJy at 4.85GHz in the 6.0sr declination band 0deg<Dec.<+75deg (excluding the 0.05sr region 12h40m<R.A.<14h40m, 0deg<Dec.<+5deg) and with radio sources stronger than 80mJy in the 3.4sr area 0h<R.A.<20h, -40deg<Dec.<0deg (plus the region 12h40m<R.A.<14h40m, 0deg<Dec.<+5deg). Fields containing new candidate identifications were mapped by the VLA at 4.86GHz with about 15" FWHM resolution. Difficult cases were confirmed or rejected with the aid of accurate (sigma~1") radio and optical positions. The final sample of 354 identifications in Omega=9.4sr is reliable and large enough to contain statistically useful numbers of radio-loud FIR galaxies and quasars. The logarithmic FIR/radio flux ratio parameter q can be used to distinguish radio sources powered by "starbursts" from those powered by "monsters." Starbursts and normal spiral galaxies in a lambda=60um flux-limited sample have a narrow (sigma_q=0.14+/-0.01) q distribution with mean <q>=2.74+/-0.01, and none have "warm" FIR spectra [{alpha}(25um, 60um)<1.5]. The absence of radio-quiet (but not completely silent) blazars indicates that nearly all blazars become optically thin at frequencies {nu}<~100GHz. Nonthermal sources with steep FIR/optical spectra and dust-embedded sources visible only at FIR and radio wavelengths must be very rare.
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- ID:
- ivo://CDS.VizieR/J/A+A/432/69
- Title:
- Extremely Red Objects XMM-Newton observations
- Short Name:
- J/A+A/432/69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a deep (about 80ks) XMM-Newton survey of the largest sample of near-infrared selected Extremely Red Objects (R-K>5) available to date to Ks<~19.2.
- ID:
- ivo://CDS.VizieR/J/PASJ/60/209
- Title:
- Faint companions around YSOs in TMC
- Short Name:
- J/PASJ/60/209
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted near-infrared spectroscopy of 26 faint objects around young stellar objects in the Taurus molecular cloud. These objects were detected during a course of near-infrared coronagraphic searches for companions around 72 young stellar objects with the Subaru Telescope and the near-infrared coronagraph CIAO (coronagraphic imager with adaptive optics). A comparison of the Subaru and HST archive images revealed that three central stars and faint companions share common proper motions, suggesting that they are physically associated with each other. None of the 26 sources show deep water absorption bands at near-infrared, except for DH Tau B. This result indicates that all of them, but DH Tau B, have a high photospheric temperature or a large amount of excess from circumstellar materials.
- ID:
- ivo://CDS.VizieR/J/ApJ/405/94
- Title:
- Far-infrared emission from 5 galaxy clusters
- Short Name:
- J/ApJ/405/94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have analyzed IRAS image data using a random position, multiple-aperture photometry method to study diffuse far-infrared emission for a sample of 56 clusters of galaxies at 60 and 100um. Five of the clusters in the sample exhibit excess far-infrared emission, but at low levels of significance. For A496 (Perseus) and MKW 1, this emission appears to be associated with a strong point source: in A2344, the observed excess is probably due to a foreground cirrus cloud. Two clusters, A262 and A2670, show evidence for extended diffuse emission. This emission is unlikely to be due to point sources associated with the clusters. In these two clusters, the diffuse emission shows evidence of being extended along the cluster's major axis. Far-infrared maps at 60 and 100um are presented for these five clusters. We find that contamination due to diffuse Galactic cirrus represents the major source of uncertainty in the measurement of far-infrared emission. The mean cluster fluxes for the sample as a whole are 44 and 107mJy for a 4' diameter aperture at 60 and 100um, respectively. The corresponding fluxes for a 10' diameter aperture are 138 and 253mJy at 60 and 100um. Photometry for the entire sample shows statistical evidence for excess emission at 60um associated with clusters in apertures 4' and 10' in diameter. This result is unlikely to be caused by random sampling errors. The flux distributions are analyzed for evidence that excess far-infrared radiation correlates with cluster environmental characteristics. Although we find evidence that poorer X-ray clusters are stronger far-infrared emitters, this result is tentative owing to the small sample sizes involved. The far-infrared luminosities, dust temperatures, and dust masses which these results imply are also presented. Finally, the origin and possible heating mechanism for dust in the intracluster medium is discussed.
- ID:
- ivo://CDS.VizieR/J/A+A/418/131
- Title:
- Far-infrared loops in the 2nd Galactic Quadrant
- Short Name:
- J/A+A/418/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an investigation of the large structure of the diffuse interstellar medium in the 2nd Galactic Quadrant (90{deg}<=l<=180{deg}). 145 loops were identified on IRAS based on far-infrared maps. Our catalogue lists their basic physical properties. The distribution clearly suggests that there is an efficient process that can generate loop-like features at high galactic latitudes. Distances are provided for 30 loops. We also give an observational estimate on the volume filling factor of the hot gas in the Local Arm, 4.6%<=f_2nd_<6.4%.
- ID:
- ivo://CDS.VizieR/J/A+A/594/A59
- Title:
- Far-IR lines in YSOs Herschel-PACS
- Short Name:
- J/A+A/594/A59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Gas plays a major role in the dynamical evolution of young stellar objects (YSOs). Its interaction with the dust is the key to our understanding planet formation later on in the protoplanetary disc stage. Studying the gas content is therefore a crucial step towards understanding YSO and planet formation. Such a study can be made through spectroscopic observations of emission lines in the far-infrared, where some of the most important gas coolants emit, such as the [OI] ^3^P_1_-^3^P_2_ transition at 63.18 microns. We provide a compilation of observations of far-IR lines in 362 young stellar objects covering all evolutionary stages, from Class 0 to Class III with debris discs. In the present paper we focus on [OI] and o-H_2_O emission at 63 microns. We have retrieved all the available Herschel-PACS spectroscopic observations at 63 microns that used the dominant observing mode, the chop-nod technique. We provide measurements of line fluxes for the [OI] ^3^P_1_-^3^P_2_ and o-H_2_O 8_08_-7_17_ transitions at 63 microns computed using different methods. Taking advantage of the PACS IFU, we check for spatially extended emission and further study the presence of multiple dynamical components in line emission. The final compilation consists of line and continuum fluxes at 63 microns for a total of 362 young stellar objects (YSOs). We detected [OI] line emission at 63 microns in 194 sources out of 362, and line absorption in another five sources. o-H_2_O was detected in 42 sources. We find evidence of extended [OI] emission in 77 sources, and detect 3sigma residual emission in 71 of them. The number of sources showing extended emission decays from Class 0 to Class II. We also looked for different components contributing to the line emission, and found evidence for multiple components in 30 sources. We explored correlations between line emission and continuum emission and find a clear correlation between WISE fluxes from 4.6 to 22 microns and [OI] line emission. We conclude that the observed emission is typically a combination of disc/envelope and jet emission.
- ID:
- ivo://CDS.VizieR/J/ApJ/753/18
- Title:
- Far-IR spectrum of ethylene oxide (CH_2_-O-CH_2_)
- Short Name:
- J/ApJ/753/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-resolution Fourier Transform Infrared spectroscopy (FTIR) spectra of ethylene oxide (CH_2_-O-CH_2_) have been measured in the far-infrared region using synchrotron radiation. A total of 1182 lines between 15/cm (450GHz) and 73/cm (2.2THz) were assigned, with J_max_=64, expanding upon previous studies that had recorded spectra up to 12/cm, J_max_=49. All available data were co-fitted to provide greatly improved rotational constants for the ground vibrational state that are capable of predicting transitions up to 73/cm.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A77
- Title:
- FEEDBACK from the NGC7538 HII region
- Short Name:
- J/A+A/659/A77
- Date:
- 14 Mar 2022 07:43:25
- Publisher:
- CDS
- Description:
- The interaction of expanding HII regions with their environmental cloud is one of the central questions driving the SOFIA legacy program FEEDBACK. We want to understand the interaction of the prototypical NGC7538 HII region with the neighboring molecular cloud hosting several active star-forming regions. Using the Stratospheric Observatory for Infrared Astronomy (SOFIA), we mapped an area of ~210'^2^ (~125pc^2^) around NGC7538 in the velocity-resolved ionized carbon fine-structure line [CII] at 1.9THz (158um). Complementary observed atomic carbon [CI] at 492GHz and high-J CO(8-7) data, as well as the archival near- and far-infrared, cm continuum, CO(3-2), and HI data are folded into the analysis. The ionized carbon [CII] data reveal rich morphological and kinematic structures. While the overall morphology follows the general ionized gas that is also visible in the radio continuum emission, the channel maps show multiple bubble-like structures with sizes on the order of ~80-100'' (~1.0-1.28pc). While at least one of them may be an individual feedback bubble driven by the main exciting sources of the NGC7538 HII region (the O3 and O9 stars IRS6 and IRS5), the other bubble-like morphologies may also be due to the intrinsically porous structure of the HII region. An analysis of the expansion velocities around 10km/s indicates that thermal expansion is not sufficient but that wind-driving from the central O-stars is required. The region exhibits a general velocity gradient across, but we also identify several individual velocity components. The most blue-shifted [CII] component has barely any molecular or atomic counterparts. At the interface to the molecular cloud, we find a typical photon-dominated region (PDR) with a bar-shape. Ionized C+, atomic C0 and molecular carbon CO show a layered structure in this PDR. The carbon in the PDR is dominated by its ionized C+ form with atomic C0 and molecular CO masses of ~0.45+/-0.1M_{sun}_ and ~1.2+/-0.1M_{sun}_, respectively, compared to the ionized carbon C+ in the range of 3.6-9.7M_{sun}_. This bar-shaped PDR exhibits a velocity-gradient across, indicating motions along the line of sight toward the observer. Even if it is shown to be dominated by two nearby exciting sources (IRS6 and IRS5), the NGC7538 HII region exhibits a diverse set of substructures that interact with each other as well as with the adjacent cloud. Compared to other recent [CII] observations of HII regions (e.g., Orion Veil, RCW120, RCW49), the bubble-shape morphologies revealed in [CII] emission that are indicative of expanding shells are recurring structures of PDRs.
- ID:
- ivo://CDS.VizieR/J/ApJ/875/129
- Title:
- FeI lines in NIR spectra of Arcturus & mu Leo
- Short Name:
- J/ApJ/875/129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- For a detailed analysis of stellar chemical abundances, high-resolution spectra in the optical have mainly been used, while the development of near-infrared (NIR) spectrograph has opened new wavelength windows. Red giants have a large number of resolved absorption lines in both the optical and NIR wavelengths, but the characteristics of the lines in different wave passbands are not necessarily the same. We present a selection of FeI lines in the z', Y, and J bands (0.91-1.33{mu}m). On the basis of two different lists of lines in this range, the Vienna Atomic Line Database (VALD) and the catalog published by Melendez & Barbuy in 1999 (MB99; Cat. J/ApJS/124/527), we selected sufficiently strong lines that are not severely blended and compiled lists with 107 FeI lines in total (97 and 75 lines from VALD and MB99, respectively). Combining our lists with high-resolution ({lambda}/{Delta}{lambda}=28000) and high signal-to-noise (>500) spectra taken with an NIR spectrograph, WINERED, we present measurements of the iron abundances of two prototype red giants: Arcturus and {mu} Leo. A bootstrap method for determining the microturbulence and abundance together with their errors is demonstrated. The standard deviations of log{epsilon}_Fe_ values from individual FeI lines are significantly smaller when we use the lines from MB99 instead of those from VALD. With the MB99 list, we obtained {xi}=1.20+/-0.11km/s and log{epsilon}_Fe_=7.01+/-0.05dex for Arcturus, and {xi}=1.54+/-0.17km/s and log{epsilon}_Fe_=7.73+/-0.07dex for {mu} Leo. These final values show better agreements with previous values in the literature than the corresponding values we obtained with VALD.
- ID:
- ivo://CDS.VizieR/J/A+A/606/A50
- Title:
- Fe-rich silicate analogues mass absorption coeff.
- Short Name:
- J/A+A/606/A50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To model the cold dust emission observed in the diffuse interstellar medium, in dense molecular clouds or in cold clumps that could eventually form new stars, it is mandatory to know the physical and spectroscopic properties of this dust and to understand its emission. This work is a continuation of previous studies aiming at providing astronomers with spectroscopic data of realistic cosmic dust analogues for the interpretation of observations. The aim of the present work is to extend the range of studied analogues to iron-rich silicate dust analogues. Ferromagnesium amorphous silicate dust analogues were produced by a sol-gel method with a mean composition close to Mg_1-x_Fe_x_SiO_3_ with x=0.1, 0.2, 0.3, 0.4. Part of each sample was annealed at 500{deg}C for two hours in a reducing atmosphere to modify the oxidation state of iron. We have measured the mass absorption coefficient (MAC) of these eight ferromagnesium amorphous silicate dust analogues in the spectral domain 30-1000um for grain temperature in the range 10-300K and at room temperature in the 5-40um range. The MAC of ferromagnesium samples behaves in the same way as the MAC of pure Mg-rich amorphous silicate samples. In the 30-300K range, the MAC increases with increasing grain temperature whereas in the range 10-30K, we do not see any change of the MAC. The MAC cannot be described by a single power law in {lambda}^-{beta}^. The MAC of the samples does not show any clear trend with the iron content. However the annealing process has, on average, an effect on the MAC that we explain by the evolution of the structure of the samples induced by the processing. The MAC of all the samples is much higher than the MAC calculated by dust models. The complex behavior of the MAC of amorphous silicates with wavelength and temperature is observed whatever the exact silicate composition (Mg vs. Fe amount). It is a universal characteristic of amorphous materials, and therefore of amorphous cosmic silicates, that should be taken into account in astronomical modeling. The enhanced MAC of the measured samples compared to the MAC calculated for cosmic dust model implies that dust masses are overestimated by the models.
