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- ID:
- ivo://CDS.VizieR/J/A+A/581/A33
- Title:
- Nearby radio galaxies FUV to MIR properties
- Short Name:
- J/A+A/581/A33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate whether the far-UV continuum of nearby radio galaxies is due solely to the parent galaxy that passively evolves, or if it reveals evidence for the presence of other star-forming or non-stellar components. If the UV excess is due to an additional radiation component, we compare this with other properties such as radio power, optical spectral type (e.g. high- and low-excitation galaxies), and the strength of the emission lines. We also discuss the possible correlation between the ultraviolet flux, IR properties, and the central black hole mass. We used a sample of low-luminosity B2 radio galaxies and a small sample of higher luminosity 3C radio galaxies at comparable redshift (z<0.2). Spectral energy distributions (SEDs) were constructed using a number of on-line databases that are freely available now: GALEX, SDSS, 2MASS, and WISE. These were compared with model SEDs of early-type galaxies with passively evolving stellar populations at various ages (typically 0.5-1.3x10^9^ years). We established whether a second component was needed to obtain a satisfactory fit with the observed overall SED. We introduce the parameter XUV, which measures the excess slope of the UV continuum between 4500 and 2000{AA} with respect to the UV radiation produced by the underlying old galaxy component. We find that the UV excess as measured by XUV is usually small or absent in low-luminosity (FR I) sources, but sets in abruptly at the transition radio power, above which we find mostly FRII sources. XUV behaves very similarly to the strength of the optical emission lines (in particular H{alpha}). Below P_1.4GHz_<10^24^W/Hz XUV is close to zero. XUV correlates strongly with the H{alpha} line strength, but only in sources with strong H{alpha} emission. We discuss whether the line emission might be due to photoionization by radiation from the parent galaxy, possibly with additional star formation, or if it requires the presence of a non-stellar active galactic nucleus component. XUV and the slope of the mid-IR are strongly correlated, as measured by the WISE bands in the interval 3.4 to 22{mu}m, in the sense that sources with a strong UV excess also have stronger IR emission. There is an inverse correlation between XUV and central black hole mass: the M_BH_ of objects with strong UV excess is on average two to three times less massive than that of objects without UV excess. Low-luminosity radio galaxies tend to be more massive and contain more massive black holes.
- ID:
- ivo://CDS.VizieR/J/MNRAS/419/1637
- Title:
- Nearby red clump stars JHK observations
- Short Name:
- J/MNRAS/419/1637
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-precision ({sigma}_mag_<0.10) new JHK observations of 226 of the brightest and nearest red clump stars in the solar neighbourhood are used to determine distance moduli for the Large Magellanic Cloud (LMC). The resulting K- and H-band values of 18.47+/-0.02 and 18.49+/-0.06 imply that any correction to the K-band Cepheid PL relation due to metallicity differences between Cepheids in the LMC and the solar neighbourhood must be quite small.
- ID:
- ivo://CDS.VizieR/J/MNRAS/458/4512
- Title:
- Nearby Seyfert galaxies FIR emissions
- Short Name:
- J/MNRAS/458/4512
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present far-infrared (FIR) 70-500{mu}m imaging observations obtained with Herschel/Photodetector Array Camera (PACS) and Spectral and Photometric Imaging REceiver (SPIRE) of 33 nearby (median distance of 30Mpc) Seyfert galaxies from the Revised Shapley-Ames (RSA) catalogue. We obtain the FIR nuclear (r=1kpc and r=2kpc) and integrated spectral energy distributions (SEDs). We estimate the unresolved nuclear emission at 70{mu}m and we fit the nuclear and integrated FIR SEDs with a grey body model. We find that the integrated FIR emission of the RSA Seyferts in our sample is dominated by emission from the host galaxy, with dust properties similar to those of normal galaxies (non-AGN). We use four criteria to select galaxies whose nuclear 70{mu}m emission has a significant AGN contribution: (1) elevated 70/160{mu}m flux ratios, (2) spatially resolved, high dust temperature gradient, (3) 70{mu}m excess emission with respect to the fit of the FIR SEDs with a grey body, and (4) excess of nuclear SFR obtained from 70{mu}m over SFR from mid-infrared indicators. 16 galaxies (48 per cent of the initial sample) satisfy at least one of these conditions, whereas 10 satisfy half or more. After careful examination of these, we select six bona fide candidates (18 per cent of the initial sample) and estimate that ~40-70 per cent of their nuclear (r=1-2kpc) 70{mu}m emission is contributed by dust heated by the AGN.
- ID:
- ivo://CDS.VizieR/J/AJ/123/2806
- Title:
- Nearby stars in the NLTT catalogue
- Short Name:
- J/AJ/123/2806
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We are currently undertaking a program aimed at identifying previously unrecognized late-type dwarfs within 20pc of the Sun. As a first step, we have cross-referenced Luyten's NLTT proper-motion catalog (Cat. <I/98>) against the second incremental release of the Two Micron All Sky Survey (2MASS) Point Source Catalog (Cat. <B/2mass>) and use optical/infrared colors, derived by combining Luyten's m_r_ estimates with 2MASS data, to identify candidate nearby stars. This paper describes the definition of a reference sample of 1245 stars and presents a compilation of literature data for more than one-third of the sample. Only 274 stars have trigonometric parallax measurements, but we have used data for nearby stars with well-determined trigonometric parallaxes to compute color-magnitude relations in the (M_V_, V-K), (M_V_, V-I), and (M_I_, I-J) planes and use those relations to determine photometric parallaxes for NLTT stars with optical photometry. Based on the 2MASS JHKs data alone, we have identified a further 42 ultracool dwarfs (J-Ks>0.99) and use J-Ks colors to estimate photometric parallaxes. Combining these various techniques, we identify 308 stars with formal distances of less than 20 pc, while a further 46 have distance estimates within 1{sigma} of survey limit. Of these 354 stars, 75, including 39 of the ultracool dwarfs, are new to nearby-star catalogs. Two stars with both optical and near-infrared photometry are potential additions to the immediate solar neighborhood, with formal distance estimates of less than 10 pc.
- ID:
- ivo://CDS.VizieR/J/AJ/126/2449
- Title:
- Nearby ultracool dwarfs in galactic plane
- Short Name:
- J/AJ/126/2449
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Surveys for nearby low-luminosity dwarfs tend to avoid the crowded regions of the Galactic plane. We have devised near-infrared color-magnitude and color-color selection criteria designed to identify late-type M and early-type L dwarfs within 12pc of the Sun. We use those criteria to search for candidates within the regions of the Galactic plane (|b|<10{deg}) covered by the Second Incremental Data Release from the Two Micron All Sky Survey (<II/241>). Detailed inspection of the available photographic images of the resulting 1299 candidates confirms only two as ultracool dwarfs. Both are known proper-motion stars, identified in the recent survey by Lepine et al. (2003, Cat. <J/AJ/125/1598>). Despite the low numbers, the inferred surface density is consistent with comparable surveys at higher latitudes. We discuss the implications for the luminosity function and consider means of improving the efficiency and scope of photometric surveys in the plane.
- ID:
- ivo://CDS.VizieR/J/A+A/422/1023
- Title:
- Nearby visual double stars UBVRI photometry
- Short Name:
- J/A+A/422/1023
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present accurate CCD astrometric and photometric data for 31 nearby visual double stars in the standard filters BVRI. The observations were collected with a 1.3-m telescope in 2001-2002. The results consist of relative astrometric positions (epoch, angular separation and position angle) and differential BVRI photometry of the components. Mean errors are: 0.01" for the separation; 0.06{deg} for the position angle; and 0.015mag for the photometric data. Comparing the relative positions at different epochs, we evaluate the physical association of the systems. We additionally derive fractional masses and true separations for the most probable binary systems and, whenever orbits are available, also total and component masses.
- ID:
- ivo://CDS.VizieR/J/A+A/510/A1
- Title:
- Near infrared imaging of cometary globule CG12
- Short Name:
- J/A+A/510/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Cometary globule 12 is a relatively little investigated medium- and low mass star forming region 210pc above the Galactic plane. This study sets out to discover the possibly embedded members of the CG 12 stellar cluster, to refine the NIR photometry of the known member stars and to study the star formation activity in CG 12 and its relation to the distribution of molecular gas, dust and mid- to far-infrared emission in the cloud. NIR J, H, and Ks imaging and stellar photometry is used to analyse the stellar content and the structure of CG 12.
- ID:
- ivo://CDS.VizieR/J/AJ/137/3149
- Title:
- Near-infrared imaging polarimetry in S106
- Short Name:
- J/AJ/137/3149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of wide-field JHKS polarimetry toward the HII region S106 using the Infrared Survey Facility telescope. Our polarimetry data revealed an extended (up to ~5') polarized nebula over S106. We confirmed the position of the illuminating source of most of the nebula as consistent with S106 IRS 4 through an analysis of polarization vectors. The bright portion of the polarized intensity is consistent with the red wing component of the molecular gas.
- ID:
- ivo://CDS.VizieR/J/ApJ/824/95
- Title:
- Near-infrared imaging polarimetry of GGD 27
- Short Name:
- J/ApJ/824/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Near-infrared imaging polarimetry in the J, H, and K_ s_ bands was carried out for GGD 27 in the dark cloud Lynds 291. Details of an infrared reflection nebula associated with the optical nebulosity GGD27 and the infrared nebula GGD 27 IRS are presented. Aperture photometry of 1263 point-like sources, detected in all three bands, was used to classify them based on a color-color diagram, and the linear polarization of several hundred sources was determined, with the latter used to map the magnetic field structure around GGD 27. This field, around GGD 27 IRS, appears to be associated with the extended CO outflow of IRAS 18162-2048; however, there are partly distorted or bent components in the field. The Chandrasekhar-Fermi method gives an estimate of the magnetic field strength as ~90{mu}G. A region associated with GGD 27 IRS is discovered to have a circular polarization in the range of ~2%-11% in the K_s_ band. The circular polarization has an asymmetric positive/negative pattern and extends out to ~120" or 1.0pc. The circular and linear polarization patterns are explained as resulting from a combination of dense inner and fainter outer lobes, suggesting episodic outflow.
