- ID:
- ivo://CDS.VizieR/J/A+A/499/483
- Title:
- NIR observations of sources in galactic center
- Short Name:
- J/A+A/499/483
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a study that uses AO assisted observations obtained at the ESO VLT in the NIR H-band and 7 intermediate bands covering the NIR K-band. A comparison of the resulting SEDs with a blackbody of variable extinction then allows us to determine the presence and strength of a CO absorption feature to distinguish between early and late type stars. This new method is suitable for classifying K giants (and later), as well as B2 main sequence (and earlier) stars that are brighter than 15.5mag in the K band in the central parsec. Extremely red objects and foreground sources can also be reliably removed from the sample. Several results, such as the shape of the KLF and the spatial distribution of both early and late type stars, confirm and extend previous works. The distribution of the early type stars can be fitted with a steep power law (beta_1"_=-1.49+/-0.12), alternatively with a broken power law, beta_1-10"_=-1.08+/-0.12, beta_10-20"_=-3.46+/-0.58, since we find a drop in the early type density at ~10". We also detect early type candidates outside of 0.5pc in significant numbers for the first time. The late type density function shows an inversion in the inner 6", with a power-law slope of beta_R<6"_=0.17+/-0.09. The late type KLF has a power-law slope of 0.30+/-0.01, closely resembling the KLF obtained for the bulge of the Milky Way. The early type KLF has a much flatter slope of (0.14+/-0.02). Our results agree best with an in-situ star formation scenario.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/511/A18
- Title:
- NIR observations of stars near SgrA*
- Short Name:
- J/A+A/511/A18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nuclear star cluster of the Galaxy is an important template for understanding its extragalactic counterparts, which can currently not be resolved into individual stars. Important drawbacks of observations of the Galactic center are, however, the presence of strong and spatially highly variable interstellar extinction and extreme crowding of the sources, which makes the use of adaptive optics techniques necessary. Both points pose serious obstacles to precise photometry that is needed for analyzing the stellar population. The aims of this work are to provide accurate photometry in multiple near-infrared broadband filters, to determine the power-law index of the extinction-law toward the central parsec of the Galaxy, to provide measurements of the absolute extinction toward the Galactic center, and finally to measure the spatial variability of extinction on arcsecond scales.
- ID:
- ivo://CDS.VizieR/J/A+AS/126/479
- Title:
- NIR photometry of IRAS sources. III
- Short Name:
- J/A+AS/126/479
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the near infrared photometry of a new sample of 225 IRAS sources, many of them previously unidentified in the literature, selected because their far infrared colours are similar to those shown by known planetary nebulae. The results obtained are used to establish the main source of near infrared emission. Combining this information with the far infrared IRAS data and a few additional criteria we determine the nature and evolutionary stage of all the sources observed so far, including those for which near infrared photometry was previously reported in Papers I (Manchado et al., 1989A&A...214..139M) and II (Garcia-Lario et al., 1990A&AS...82..497G).
- ID:
- ivo://CDS.VizieR/J/MNRAS/384/1502
- Title:
- NIR photometry of X-ray luminous BCGs
- Short Name:
- J/MNRAS/384/1502
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the near-infrared evolution of brightest cluster galaxies (BCGs) from a sample of rich galaxy clusters since z~1. By employing an X-ray selection of LX>10^44^erg/s, we limit environmental effects by selecting BCGs in comparably high-density regions. We find a positive relationship between X-ray and near-infrared luminosity for BCGs in clusters with LX>5x10^44^erg/s. Applying a correction for this relation, we reduce the scatter in the BCG absolute magnitude by a factor of 30 per cent. The near-infrared J-K colour evolution demonstrates that the stellar population in BCGs has been in place since at least z=2, and that we expect a shorter period of star formation than that predicted by current hierarchical merger models. We also confirm that there is a relationship between 'blue' J-K colour and the presence of BCG emission lines associated with star formation in cooling flows.
- ID:
- ivo://CDS.VizieR/J/ApJS/213/22
- Title:
- NIR polarimetry in the Central Molecular Zone
- Short Name:
- J/ApJS/213/22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out near-infrared polarimetry toward the boundary of the Central Molecular Zone, in the field of (-1.{deg}4<~l<~-0.{deg}3 and 1.{deg}0<~l<~2.{deg}9,|b|<~0.{deg}1), using the near-infrared polarimetric camera SIRPOL on the 1.4m Infrared Survey Facility telescope. We have selected 112 intrinsically polarized sources on the basis of the estimate of interstellar polarization on Stokes Q/I-U/I planes. The selected sources are brighter than K_S_=14.5mag and have polarimetric uncertainty {delta}P<1%. Ten of these distinctive polarized sources are fit well with spectral energy distributions of young stellar objects when using the photometry in the archive of the Spitzer Space Telescope mid-infrared data. However, many sources have spectral energy distributions of normal stars suffering from heavy interstellar extinction; these might be stars behind dark clouds. Due to the small number of distinctive polarized sources and candidates of young stellar objects, we cannot judge if they are declining in number outside the Central Molecular Zone. Many massive candidates for young stellar objects in the literature have only small intrinsic polarization. This might suggest that their masses are 4-15M_{sun}_, whose intrinsic polarization has been expected to be small.
- ID:
- ivo://CDS.VizieR/J/A+A/534/A117
- Title:
- NIR polarimetry of sources near SgrA*
- Short Name:
- J/A+A/534/A117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galactic Center offers unique opportunities to study stellar and bow-shock polarization effects in a dusty environment. The goals of this work are to provide near-infrared (NIR) polarimetry of the stellar sources in the central parsec at the resolution of an 8m telescope for the first time, along with new insights into the nature of the known bright bow-shock sources. We use adaptive-optics assisted observations obtained at the ESO VLT in the H- and Ks-band, applying both high-precision photometric methods specifically developed for crowded fields and a newly established polarimetric calibration for NACO to produce polarization maps of the central 3"x10", in addition to spatially resolved polarimetry and a flux variability analysis on the extended sources in this region.
- ID:
- ivo://CDS.VizieR/J/MNRAS/437/3603
- Title:
- NIR proper motion catalogue from UKIDSS-LAS
- Short Name:
- J/MNRAS/437/3603
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The United Kingdom Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS) began in 2005, with the start of the UKIDSS programme as a 7 year effort to survey roughly 4000deg^2^ at high Galactic latitudes in Y, J, H and K bands. The survey also included a significant quantity of two epoch J band observations, with an epoch baseline greater than 2 years to calculate proper motions. We present a near-infrared proper motion catalogue for the 1500deg^2^ of the two epoch LAS data, which includes 135625 stellar sources and a further 88324 with ambiguous morphological classifications, all with motions detected above the 5{sigma} level. We developed a custom proper motion pipeline which we describe here. Our catalogue agrees well with the proper motion data supplied for a 300deg^2^ subset in the current Wide Field Camera Science Archive (WSA) 10th data release (DR10) catalogue, and in various optical catalogues, but it benefits from a larger matching radius and hence a larger upper proper motion detection limit. We provide absolute proper motions, using LAS galaxies for the relative to absolute correction. By using local second-order polynomial transformations, as opposed to linear transformations in the WSA, we correct better for any local distortions in the focal plane, not including the radial distortion that is removed by the UKIDSS pipeline. We present the results of proper motion searches for new brown dwarfs and white dwarfs. We discuss 41 sources in the WSA DR10 overlap with our catalogue with proper motions >300mas/yr, several of which are new detections. We present 15 new candidate ultracool dwarf binary systems.
- ID:
- ivo://CDS.VizieR/J/ApJ/796/7
- Title:
- NIR spectral analysis of star-forming galaxies
- Short Name:
- J/ApJ/796/7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we follow up on our previous detection of nuclear ionized outflows in the most massive (log(M_*_/M_{sun}_)>=10.9) z~1-3 star-forming galaxies (SFGs) by increasing the sample size by a factor of six (to 44 galaxies above log(M_*_/M_{sun}_)>=10.9) from a combination of the SINS/zC-SINF, LUCI, GNIRS, and KMOS^3D^ spectroscopic surveys.
- ID:
- ivo://CDS.VizieR/J/ApJ/806/L35
- Title:
- NIR spectroscopy of COSMOS FIR galaxies
- Short Name:
- J/ApJ/806/L35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used FMOS on Subaru to obtain near-infrared spectroscopy of 123 far-infrared-selected galaxies in COSMOS and the key rest-frame optical emission lines. This is the largest sample of infrared galaxies with near-infrared spectroscopy at these redshifts. The far-infrared selection results in a sample of galaxies that are massive systems that span a range of metallicities in comparison with previous optically selected surveys, and thus has a higher active galactic nucleus (AGN) fraction and better samples the AGN branch. We establish the presence of AGNs and starbursts in this sample of (U)LIRGs selected as Herschel-PACS and Spitzer-MIPS detections in two redshift bins (z~0.7 and z~1.5) and test the redshift dependence of diagnostics used to separate AGNs from star formation dominated galaxies. In addition, we construct a low-redshift (z~0.1) comparison sample of infrared-selected galaxies and find that the evolution from z~1.5 to today is consistent with an evolving AGN selection line and a range of ISM conditions and metallicities from the models of Kewley et al. (2013ApJ...774L..10K). We find that a large fraction of (U)LIRGs are BPT-selected AGNs using their new redshift-dependent classification line. We compare the position of known X-ray-detected AGNs (67 in total) with the BPT selection and find that the new classification line accurately selects most of these objects (>70%). Furthermore, we identify 35 new (likely obscured) AGNs not selected as such by their X-ray emission. Our results have direct implications for AGN selection at higher redshift with either current (MOSFIRE, KMOS) or future (PFS, MOONS) spectroscopic efforts with near-infrared spectral coverage.
- ID:
- ivo://CDS.VizieR/J/A+A/434/149
- Title:
- NIR spectroscopy of luminous IR galaxies
- Short Name:
- J/A+A/434/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on near-infrared medium-resolution spectroscopy of a sample of luminous and ultra luminous infrared galaxies (LIRGs-ULIRGs), carried out with SOFI at the ESO 3.5m New Technology Telescope.
