- ID:
- ivo://CDS.VizieR/J/AJ/150/17
- Title:
- A catalog of point sources toward NGC 1333
- Short Name:
- J/AJ/150/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- I present a catalog of point-source objects toward NGC 1333, resolving a wide variety of confusion about source names (and occasionally positions) in the literature. I incorporate data from optical to radio wavelengths, but focus most of the effort on being complete and accurate from J (1.25{mu}m) to 24{mu}m. The catalog encompasses 52^{deg}^<R.A.<52.5{deg} and 31{deg}<decl.<31.6{deg}. Cross-identifications include those from more than 25 papers and catalogs from 1994 to 2014, primarily those in wide use as origins of nomenclature. Gaps in our knowledge are identified, with the most important being a lack of spectroscopy for spectral types or even confirmation of youth and/or cluster membership. I fit a slope to the spectral energy distribution (SED) between 2 and 24{mu}m for the members (and candidate members) to obtain an SED classification, and I compare the resulting classes to those for the same sources in the literature, and for an SED fit between 2 and 8{mu}m. While there are certainly differences, for the majority of the sources, there is good agreement.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/412/127
- Title:
- ACCESS. II. Shapley galaxies FUV-FIR photometry
- Short Name:
- J/MNRAS/412/127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present panoramic Spitzer/MIPS mid- and far-infrared (MIR/FIR) and GALEX ultraviolet imaging of the most massive and dynamically active system in the local Universe, the Shapley supercluster at z=0.048, covering the five clusters that make up the supercluster core. We combine these data with existing spectroscopic data from 814 confirmed supercluster members to produce the first study of a local rich cluster including both ultraviolet and infrared luminosity functions (LFs).
- ID:
- ivo://CDS.VizieR/J/ApJ/710/597
- Title:
- Accretion in disks in Cep OB2
- Short Name:
- J/ApJ/710/597
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present accretion rates for a large number of solar-type stars in the Cep OB2 region, based on U-band observations. Our study comprises 95 members of the ~4Myr old cluster Tr 37 (including 20 "transition" objects (TOs)), as well as the only classical T Tauri star (CTTS) in the ~12Myr old cluster NGC 7160. The stars show different disk morphologies, with the majority of them having evolved and flattened disks. The typical accretion rates are about 1 order of magnitude lower than in regions aged 1-2Myr, and we find no strong correlation between disk morphology and accretion rates. Although half of the TOs are not accreting, the median accretion rates of normal CTTS and accreting "transition" disks are similar (~3x10^-9^ and 2x10^-9^M_{sun}_/yr, respectively). Comparison with other regions suggests that the TOs observed at different ages do not necessarily represent the same type of objects, which is consistent with the fact that the different processes that can lead to reduced IR excess/inner disk clearing (e.g., binarity, dust coagulation/settling, photoevaporation, giant planet formation) do not operate on the same timescales.
- ID:
- ivo://CDS.VizieR/J/ApJ/769/21
- Title:
- Accretion luminosities of young stars from Pf{beta}
- Short Name:
- J/ApJ/769/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work, we introduce the use of HI Pfund {beta} (Pf{beta}; 4.6538{mu}m) as a tracer of mass accretion from protoplanetary disks onto young stars. Pf{beta} was serendipitously observed in NIRSPEC and CRIRES surveys of CO fundamental emission, amounting to a sample size of 120 young stars with detected Pf{beta} emission. Using a subsample of disks with previously measured accretion luminosities, we show that Pf{beta} line luminosity is well correlated with accretion luminosity over a range of at least three orders of magnitude. We use this correlation to derive accretion luminosities for all 120 targets, 65 of which are previously unreported in the literature. The conversion from accretion luminosity to accretion rate is limited by the availability of stellar mass and radius measurements; nevertheless, we also report accretion rates for 67 targets, 16 previously unmeasured. Our large sample size and our ability to probe high extinction values allow for relatively unbiased comparisons between different types of disks.
- ID:
- ivo://CDS.VizieR/J/ApJ/694/425
- Title:
- A Chandra X-ray observation of L1251B
- Short Name:
- J/ApJ/694/425
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- I report the results of a 60ks X-ray observation of the L1251 dark cloud in Cepheus, which was acquired with the ACIS-I camera on board the Chandra X-Ray Observatory. Forty-three compact X-ray sources were detected. The field of view was centered on the position of IRAS 22376+7455, an embedded Class 0/I protostar that is closely associated with the bright CO emission core, L1251B-Core E. A very intense impulsive X-ray flare was observed from a location within the formal error ellipse of the IRAS source and in close proximity (within <~1") to a thermal continuum radio source, VLA 3. Given their small spatial offsets, the radio, far-infrared, and X-ray objects appear to be identical and consequently the likely origin and driving source of high-velocity gas flows that are observed in L1251B.
- ID:
- ivo://CDS.VizieR/J/A+A/455/903
- Title:
- ACIS-I observations of NGC 2264
- Short Name:
- J/A+A/455/903
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper's goal is to improve the member census of the NGC 2264 star-forming region and study the origin of X-ray activity in young PMS stars. We analyze a deep, 100ks long, Chandra ACIS observation covering a 17'x17' field in NGC 2264. The preferential detection in X-rays of low-mass PMS stars gives strong indications of their membership. We study X-ray activity as a function of stellar and circumstellar characteristics by correlating the X-ray luminosities, temperatures, and absorptions with optical and near-infrared data from the literature.
- ID:
- ivo://CDS.VizieR/II/260
- Title:
- Ackermann red stars
- Short Name:
- II/260
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the late 1960s Gerhard Ackermann published two lists of extremely red stars (1968ZA.....69..130A and 1970A&A.....8..315A), including what appeared to be reliable spectral classifications for a few hundred stars. The two published papers provide details of the observing and analysis, made between June and October 1968 at the Heidelberg observatory with the 25cm f/3.6 Schmidt camera together with a 10-degree UBK7 prism yielding a dispersion of 3500 {AA}/mm at the atmospheric A band (7700{AA}). Exposures on ammonia-hypersensitized Kodak I-N emulsion + RG665 filter were obtained along with direct plates on I-N emulsion as well as 103a-E + OG550, totalling 101 exposures in all. The spectra were classified by following the precepts of Cameron & Nassau (1955ApJ...122..177C) and Nassau & Velghe (1964ApJ...139..190N). Ackermann initiated photoelectric observations at I and K, but obviously the Heidelberg weather was not conducive to pursuing this. Because the calibration of the photometry on the direct plates was by necessity rather crude, Ackermann's photometric results are not reported here -- the procedures used were sufficient to identify the reddest stars, but not for much else. Approximate V magnitudes were added for all the stars -- for the most part these are merely averages of the photo-blue and -red magnitudes in both GSC-2.2 and USNO-B1.0, but their zero-point and scale should be reliable at the few-tenths magnitude level in this range. Coordinates were drawn from either UCAC2 or 2MASS depending mainly on Declination, since UCAC2 extends only to about +40 Dec in this area. The UCAC2 positions should be good to better than 0.1", and those from 2MASS to 0.2". In a few cases, such as gross overexposure in 2MASS, positions are from various Schmidt survey catalogues, as indicated with each entry. The first 13 stars of the catalog come from the concluding volume of the ZA paper; in the 1970 paper, Ackermann refers to these stars using the acronym HDK, which is adopted here. The published table gave rather rough arcminute-precision positions (for equinox 1965). Star 6 was recovered 1 degree east of the nominal place, and identified with the variable star WX CMi. Along with the positions and IDs, the table shows V magnitudes and the spectral types given in the original paper. Some of the stars are within the region covered by the ASAS-3 survey, so reliable V magnitudes are available along with beautiful lightcurves. Ackermann's second much longer list contains rough photometry from the POSS-I prints for some 400 very red stars in the Cygnus starcloud, and for 254 of these spectral types were also determined. The stars without spectral classifications comprise a diverse group including both red/reddened late-type stars and greatly obscured hotter stars, but no real astrophysical information is given for any of them beyond sheer redness -- these stars are omitted from the catalog. In consultation with Prof Ackermann, the following changes have been made to the spectral types: for stars shown in the original table with a hyphen between two types (e.g. M5-M6), this was to show that the type was uncertain to that degree (i.e. M5 or M6), for which the 'slash' notation of Nancy Houk was preferred, and thus M5-M6 becomes M5/6. One star, 78-0-144, exhibited a range in types, and it is shown as M7-M9. Ackermann also indicated a number of stars as being of very-late type with VO present (separable from the A-band), but where the star was too faint to classify accurately. He agrees these are likely to be in the range M7 to M9, and again these are shown in the slash-style notation as M7/9:, with the colon added to indicate uncertainty since the types were not explicit in the original, and sometimes a question mark for those already marked as uncertain in the original. These changes were made so that machine parsing schemes will be better able to handle the classifications.
- ID:
- ivo://CDS.VizieR/J/A+A/477/55
- Title:
- ACO 1825 and AC 114 EROs photometry
- Short Name:
- J/A+A/477/55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the properties and nature of extremely red galaxies (ERO, R-K>=5.6) found behind two lensing clusters and compare them with other known galaxy populations. New HST/ACS, Spitzer (IRAC and MIPS), and Chandra/ACIS observations of the two lensing clusters Abell 1835 and AC 114 (ACCG 114) have been obtained, combined with our earlier optical and near-IR observations and used to study EROs in these deep fields.
- ID:
- ivo://CDS.VizieR/J/ApJS/243/21
- Title:
- A complete sample of broad-line AGN from SDSS-DR7
- Short Name:
- J/ApJS/243/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new, complete sample of 14584 broad-line active galactic nuclei (AGNs) at z<0.35 is presented, which are uncovered homogeneously from the complete database of galaxies and quasars observed spectroscopically in the Sloan Digital Sky Survey Seventh Data Release. The stellar continuum is properly removed for each spectrum with significant host absorption line features, and careful analyses of the emission line spectra, particularly in the H{alpha} and H{beta} wavebands, are carried out. The broad Balmer emission line, particularly H{alpha}, is used to indicate the presence of an AGN. The broad H{alpha} lines have luminosities in a range of 10^38.5^-10^44.3^erg/s, and line widths (FWHMs) of 500-34000km/s. The virial black hole masses, estimated from the broad-line measurements, span a range of 10^5.1^-10^10.3^M_{sun}_, and the Eddington ratios vary from -3.3 to 1.3 in logarithmic scale. Other quantities such as multiwavelength photometric properties and flags denoting peculiar line profiles are also included in this catalog. We describe the construction of this catalog and briefly discuss its properties. The catalog is publicly available online. This homogeneously selected AGN catalog, along with the accurately measured spectral parameters, provides the most updated, largest AGN sample data, which will enable further comprehensive investigations of the properties of the AGN population in the low-redshift universe.
- ID:
- ivo://CDS.VizieR/J/ApJS/241/38
- Title:
- A comprehensive analysis of Spitzer supernovae
- Short Name:
- J/ApJS/241/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The mid-infrared (mid-IR) wavelength regime offers several advantages for following the late-time evolution of supernovae (SNe). First, the peaks of the SN spectral energy distributions shift toward longer wavelengths, following the photospheric phase. Second, mid-IR observations suffer less from effects of interstellar extinction. Third, and perhaps most important, the mid-IR traces dust formation and circumstellar interaction at late times (>100 days) after the radioactive ejecta component fades. The Spitzer Space Telescope has provided substantial mid-IR observations of SNe since its launch in 2003. More than 200 SNe have been targeted, but there are even more SNe that have been observed serendipitously. Here we present the results of a comprehensive study based on archival Spitzer/IRAC images of more than 1100 SN positions; from this sample, 119 SNe of various subclasses have been detected, including 45 SNe with previously unpublished mid-IR photometry. The photometry reveals significant amounts of warm dust in some cases. We perform an in-depth analysis to constrain the origin and heating mechanism of the dust, and present the resulting statistics.
