- ID:
- ivo://CDS.VizieR/J/ApJ/634/L1
- Title:
- 16{mu}m sources in the NOAO Bootes field
- Short Name:
- J/ApJ/634/L1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the 16{mu}m peak-up imager on the Infrared Spectrograph (IRS) on Spitzer, we present a serendipitous survey of 0.0392{deg}^2^ within the area of the NOAO Deep Wide-Field Survey in Bootes. Combining our results with the available Multiband Imaging Photometer for Spitzer (MIPS) 24{mu}m survey of this area, we produce a catalog of 150 16{mu}m sources brighter than 0.18mJy (3{sigma}) for which we derive measures or limits on the 16{mu}m/24{mu}m colors. Such colors are especially useful in determining redshifts for sources whose mid-infrared spectra contain strong emission or absorption features that characterize these colors as a function of redshift.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/604/A101
- Title:
- MUSE datacube of He 2-10
- Short Name:
- J/A+A/604/A101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the physical and dynamical properties of the ionized gas in the prototypical HII galaxy Henize 2-10 using MUSE integral field spectroscopy. The large-scale dynamics are dominated by extended outflowing bubbles that are probably the result of massive gas ejection from the central star forming regions. We derived a mass outflow rate dM_out_/dt~0.30M_{sun}_/yr, corresponding to mass loading factor {eta}~0.4, in the range of similar measurements in local LIRGs. Such a massive outflow has a total kinetic energy that is sustainable by the stellar winds and supernova remnants expected in the galaxy. We studied the dust extinction, electron density, and ionization conditions all across the galaxy with a classical emission line diagnostic, confirming the extreme nature of the highly star forming knots in the core of the galaxy, which show high density and high ionization parameters. We measured the gas-phase metallicity in the galaxy, taking the strong variation of the ionization parameter into account, and found that the external parts of the galaxy have abundances as low as 12+log(O/H)~8.3, while the central star forming knots are highly enriched with super solar metallicity. We found no sign of AGN ionization in the galaxy, despite the recent claim of the presence of a supermassive active black hole in the core of He 2-10. We therefore reanalyzed the X-ray data that were used to propose the presence of the AGN, but we concluded that the observed X-ray emission can be better explained with sources of a different nature, such as a supernova remnant.
- ID:
- ivo://CDS.VizieR/J/ApJS/209/30
- Title:
- MYStIX project: Bayesian matching
- Short Name:
- J/ApJS/209/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Identifying the infrared counterparts of X-ray sources in Galactic plane fields such as those of the MYStIX project presents particular difficulties due to the high density of infrared sources. This high stellar density makes it inevitable that a large fraction of X-ray positions will have a faint field star close to them, which standard matching techniques may incorrectly take to be the counterpart. Instead we use the infrared data to create a model of both the field star and counterpart magnitude distributions, which we then combine with a Bayesian technique to yield a probability that any star is the counterpart of an X-ray source. In our more crowded fields, between 10% and 20% of counterparts that would be identified on the grounds of being the closest star to an X-ray position within a 99% confidence error circle are instead identified by the Bayesian technique as field stars. These stars are preferentially concentrated at faint magnitudes. Equally importantly the technique also gives a probability that the true counterpart to the X-ray source falls beneath the magnitude limit of the infrared catalog. In deriving our method, we place it in the context of other procedures for matching astronomical catalogs.
- ID:
- ivo://CDS.VizieR/J/AJ/158/129
- Title:
- Near-infrared hydrogen & helium QSO emission lines
- Short Name:
- J/AJ/158/129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 14 near-infrared (NIR) quasar spectra observed with the Flamingos-2 NIR spectrometer instrument at the Gemini South Observatory. The targets were selected with redshifts of (0.58~<z~<0.63) to ensure the spectral wavelength range included specifically identified hydrogen and helium broad emission lines. We present measurements of their FWHM, equivalent widths, and flux ratios relative to H{alpha}. The quasars are all within the Sloan Digital Sky Survey (SDSS) Stripe 82 region which, then also provides multi-epoch rest-frame UV and optical spectroscopic observations of our targets. In future work, these data and those from Galaxy Evolution Explorer and NUV spectra will be utilized to constrain photoionization models to determine physical conditions within the broad emission line regions, such as the incident ionizing photon flux and gas density.
- ID:
- ivo://CDS.VizieR/J/A+A/642/L15
- Title:
- Near-infrared spectra for TW Hya
- Short Name:
- J/A+A/642/L15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Volatile molecules are critical to terrestrial planetary habitability, yet they are difficult to observe directly where planets form at the midplanes of protoplanetary disks. It is unclear whether the inner ~1AU of disks are volatile-poor or if this region is resupplied with ice-rich dust from colder disk regions. Dust traps at radial pressure maxima bounding disk gaps can cut off the inner disk from these types of volatile reservoirs. However, the trap retention efficiency and atomic composition of trapped dust have not been measured. We present a new technique to measure the absolute atomic abundances in the gas accreting onto T Tauri stars and infer the bulk atomic composition and distribution of midplane solids that have been retained in the disk around the young star TW Hya. We identify near-infrared atomic line emission from gas-phase material inside the dust sublimation rim of TW Hya. Gaussian decomposition of the strongest H Paschen lines isolates the inner disk hydrogen emission. We measure several key elemental abundances, relative to hydrogen, using a chemical photoionization model and infer dust retention in the disk. With a 1D transport model, we determine approximate radial locations and retention efficiencies of dust traps for different elements. Volatile and refractory elements are depleted from TW Hya's hot gas by factors of ~10^2^ and up to 10^5^, respectively. The abundances of the trapped solids are consistent with a combination of primitive Solar System bodies. Dust traps beyond the CO and N_2_ snow line cumulatively sequester 96% of the total dust flux, while the trap at 2AU, near the H_2_O snow line, retains 3%. The high depletions of Si, Mg, and Ca are explained by a third trap at 0.3AU with >95% dust retention. TW Hya sports a significant volatile reservoir rich in C- and N-ices in its outer submillimeter ring structure. However, unless the inner disk was enhanced in C by earlier radial transport, typical C destruction mechanisms and the lack of a C resupply should leave the terrestrial planet-forming region of TW Hya "dry" and carbon-poor. Any planets that form within the silicate dust trap at 0.3 AU could resemble Earth in terms of the degree of their volatile depletion.
- ID:
- ivo://CDS.VizieR/J/AJ/121/362
- Title:
- Near-Infrared Spectra of IC5117
- Short Name:
- J/AJ/121/362
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Infrared spectroscopy from 0.8 to 2.5{mu}m is presented for the planetary nebula IC5117. The emission lines of IC5117 span a wide range of ionization that includes He II, [S III], [S II], [N I], and H2. The reddening measured from the hydrogen lines is E(B-V)=0.79, most of which is probably interstellar in origin. The He/H abundance ratio is 0.113+/-0.015, with approximately 10% of the helium being doubly ionized. Using our measurements of [S II] and [S III] lines and published observations of [S IV], we find a sulfur abundance, relative to hydrogen, of N(S)/N(H)=7.8 x 10^-6^, or approximately half the solar value. Fluxes and flux limits for several lines of molecular hydrogen are presented. Measurements of 1-0 transitions, together with the limits on 2-1 transitions, indicate Tvib~Trot=1900K, suggesting a purely collisional excitation mechanism. The ortho-to-para ratio is ~3, a value that is also indicative of collisional excitation. The presence of [C I] {lambda}9850 is consistent with previous studies of IC 5117 that indicated carbon is more abundant than oxygen. IC5117 follows the trend of planetary nebulae that display bipolar outflows and H2 emission to be carbon-rich. We confirm the results of Zhang & Kwok, who reported infrared continuum emission substantially in excess of that produced by the ionized gas. This emission is most likely due to hot dust (T~1300K) and accounts for roughly half of the continuum between 1.5 and 2{mu}m.
- ID:
- ivo://CDS.VizieR/III/181
- Title:
- Near Infrared Spectra of Normal Stars
- Short Name:
- III/181
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The authors present digital spectra of O to M stars, luminosity classes V, III, and Ib in the wavelength range 5750-8950{AA}, at 15.5{AA} resolution. The stars follow well defined morphological sequences in both temperature and luminosity. This wavelength region and resolution, combined with the high sensitivity of silicon-based detectors, are very useful for spectral classification. Details of the observations, identifications of the main spectral features, and spectral lines most sensitive to temperature and luminosity are given in the paper.
- ID:
- ivo://CDS.VizieR/J/ApJ/640/579
- Title:
- Near-infrared spectra of 27 SDSS quasars
- Short Name:
- J/ApJ/640/579
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a near-infrared quasar composite spectrum spanning the wavelength range 0.58-3.5um. The spectrum has been constructed from observations of 27 quasars obtained at the NASA IRTF telescope and satisfying the criteria Ks<14.5 and M_i_<-23; the redshift range is 0.118<z<0.418. The signal-to-noise ratio is moderate, reaching a maximum of 150 between 1.6 and 1.9um. While a power-law fit to the continuum of the composite spectrum requires two breaks, a single power-law slope of alpha=-0.92 plus a 1260K blackbody provides an excellent description of the spectrum from H{alpha} to 3.5um, strongly suggesting the presence of significant quantities of hot dust in this blue-selected quasar sample. We measure intensities and line widths for 10 lines, finding that the Paschen line ratios rule out case B recombination. We compute K-corrections for the J, H, K, and Spitzer 3.6um bands, which will be useful in analyzing observations of quasars up to z=10.
- ID:
- ivo://CDS.VizieR/J/A+A/488/987
- Title:
- Near-infrared survey of R CrA cloud
- Short Name:
- J/A+A/488/987
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To understand low- to intermediate-mass star-formation in the nearby R CrA molecular cloud, we try to identify the stellar content that is accessible with near-infrared observations. We obtained a JHKs band mosaic of ~10'x60' covering the entire R CrA molecular cloud with unprecedented sensitivity. We present a catalogue of about 3500 near-infrared sources fainter than the saturation limit Ks~10mag, reaching Ks~18mag. We analysed the extended sources by inspecting their morphology and point sources by means of colour-colour and colour-magnitude diagrams. Additionally, we compared the extinction inferred from the NIR data with the line-of-sight dust emission at 1.2mm. Sources towards high dust emission but relatively low H-Ks show a projected mm-excess; these sources are either immediately surrounded by cold circumstellar material or, if too red to be a true foreground object, they are embedded in the front layer of the 1.2mm emitting dust cloud. In both cases they are most likely associated with the cloud.
- ID:
- ivo://CDS.VizieR/J/A+A/437/1135
- Title:
- Near-IR astrometry of Southern ICRF quasars
- Short Name:
- J/A+A/437/1135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high quality astrometry, along with J, H, and Ks photometry, for 30 southern International Celestial Reference Frame (ICRF) quasars observed with the ESO NTT/SOFI at La Silla. Our main purpose is to document the optical counterpart of ICRF quasars, by reporting their position in a stellar reference frame and their near-infrared photometry. Our investigation lies within the scope of extending the (radio) extragalactic reference frame into the optical range. An internal precision generally better than 10mas was obtained in positioning the near-infrared counterpart of these quasars within their stellar surroundings. The actual astrometric accuracy is estimated from the departure between the observed and the radio (VLBI) positions of quasars, and is about 35mas, mainly due to the statistical uncertainties of the stellar reference catalogue (UCAC2, Cat. <I/289>). The positional accuracy was improved to 25mas for a subset of 14 quasars observed with extended fields of view, as obtained from mosaics of overlapping images. The 3-band photometry was achieved with a precision most often better than 0.04mag, based on calibration with the 2MASS magnitudes.
