- ID:
- ivo://archive.stsci.edu/wuppe
- Title:
- Wisconsin Ultraviolet Photo-Polarimeter Experiment
- Short Name:
- WUPPE
- Date:
- 22 Jul 2020 21:33:04
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) was the spectropolarimetry component of the three ASTRO instruments that flew on Space Shuttle missions in December 1990 and March 1995. A halfwave spectropolarimeter provided medium resolution spectropolarimetry for research into the interstellar medium, hot stars, stars with circumstellar material, interacting binary stars, novae, solar system objects, and active galaxies. A Lyot analyzer obtained low resolution observations of faint targets, but due to calibration problems did not produce scientifically useful data. The WUPPE instrument provides a unique data set, one of the few providing polarimetric data in the ultraviolet portion of the spectrum.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/589/A44
- Title:
- W51 Main NH_3_ and CH_3_OH data cubes
- Short Name:
- J/A+A/589/A44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper is the third in a series of NH_3_ multilevel imaging studies in well-known, high-mass star-forming regions. The main goal is to characterize kinematics and physical conditions of (hot and dense) circumstellar molecular gas around O-type young stars. We want to map at subarcsecond resolution highly excited inversion lines of NH_3_ in the high-mass star-forming region W51 Main (distance = 5.4kpc), which is an ideal target to constrain theoretical models of high-mass star formation. Using the Karl Jansky Very Large Array (JVLA), we mapped the hot and dense molecular gas in W51 Main with ~0.2"-0.3" angular resolution in five metastable (J = K) inversion transitions of ammonia (NH_3_): (J,K) = (6, 6), (7, 7), (9, 9), (10, 10), and (13, 13). These lines arise from energy levels between ~400K and ~1700K above the ground state. We also made maps of the (free-free) continuum emission at frequencies between 25 and 36GHz.
- ID:
- ivo://CDS.VizieR/J/A+AS/124/205
- Title:
- W3 star-forming region 345 GHz survey
- Short Name:
- J/A+AS/124/205
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results are presented of the 345 GHz spectral survey toward three sources in the W 3 Giant Molecular Cloud: W 3 IRS4, W 3 IRS5 and W 3(H_2_O). Nearly 90% of the atmospheric window between 334 and 365GHz has been scanned using the James Clerk Maxwell Telescope (JCMT) down to a noise level of ~80mK per resolution element. These observations are complemented by a large amount of data in the 230GHz atmospheric window. From this data set physical conditions and beam-averaged column densities are derived for more than 14 chemically different species (over 24 different isotopes). The physical parameters derived in Paper I (Helmich et al., 1994A&A...283..626H) are confirmed by the analysis of the excitation of other species, although there is evidence that the silicon- and sulfur-bearing molecules exist in a somewhat denser and warmer environment. The densities are high, >=10^6^cm^-3^, in the three sources and the kinetic temperatures for the bulk of the gas range from 55K for IRS4 to 220K for W 3(H_2_O). The chemical differences between the three sources are very striking: silicon- and sulfur-bearing molecules such as SiO and SO_2_ are prominent toward IRS5, whereas organic molecules like CH_3_OH, CH_3_OCH_3_ and CH_3_OCHO are at least an order of magnitude more abundant toward W 3(H_2_O). Vibrationally excited molecules are also detected toward this source. Only simple molecules are found toward IRS4. The data provide constraints on the amount of deuterium fractionation and the ionization fraction in the observed regions as well. These chemical characteristics are discussed in the context of an evolutionary sequence, in which IRS5 is the youngest, W 3(H_2_O) somewhat older and IRS4, although still enigmatic, the oldest.
- ID:
- ivo://CDS.VizieR/J/ApJ/900/L10
- Title:
- X-band data of the GOTHAM Large Project for TMC-1
- Short Name:
- J/ApJ/900/L10
- Date:
- 15 Feb 2022 11:45:23
- Publisher:
- CDS
- Description:
- We present an overview of the GBT Observations of TMC-1: Hunting Aromatic Molecules Large Program on the Green Bank Telescope. This and a related program were launched to explore the depth and breadth of aromatic chemistry in the interstellar medium at the earliest stages of star formation, following our earlier detection of benzonitrile (c-C6H5CN) in TMC-1. In this work, details of the observations, use of archival data, and data reduction strategies are provided. Using these observations, the interstellar detection of propargyl cyanide (HCCCH2CN) is described, as well as the accompanying laboratory spectroscopy. We discuss these results, and the survey project as a whole, in the context of investigating a previously unexplored reservoir of complex, gas-phase molecules in pre-stellar sources. A series of companion papers describe other new astronomical detections and analyses.
- ID:
- ivo://CDS.VizieR/J/ApJ/773/92
- Title:
- XMM survey of soft background. III. Galactic halo
- Short Name:
- J/ApJ/773/92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present measurements of the Galactic halo's X-ray emission for 110 XMM-Newton sight lines selected to minimize contamination from solar wind charge exchange emission. We detect emission from few million degree gas on ~4/5 of our sight lines. The temperature is fairly uniform (median = 2.22x10^6^K, interquartile range = 0.63x10^6^K), while the emission measure and intrinsic 0.5-2.0keV surface brightness vary by over an order of magnitude (~(0.4-7)x10^-3^cm^-6^pc and ~(0.5-7)x10^-12^erg/cm2/s deg^-2^, respectively, with median detections of 1.9x10^-3^cm^-6^pc and 1.5x10^-12^erg/cm2/s deg^-2^, respectively). The high-latitude sky contains a patchy distribution of few million degree gas. This gas exhibits a general increase in emission measure toward the inner Galaxy in the southern Galactic hemisphere. However, there is no tendency for our observed emission measures to decrease with increasing Galactic latitude, contrary to what is expected for a disk-like halo morphology. The measured temperatures, brightnesses, and spatial distributions of the gas can be used to place constraints on models for the dominant heating sources of the halo. We provide some discussion of such heating sources, but defer comparisons between the observations and detailed models to a later paper.
- ID:
- ivo://CDS.VizieR/J/ApJ/862/34
- Title:
- X-ray spectral analysis of 107 MW sight lines
- Short Name:
- J/ApJ/862/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The formation mechanism of the hot gaseous halo associated with the Milky Way is still under debate. We report new observational constraints on the gaseous halo using 107 lines of sight of the Suzaku X-ray observations at 75{deg}<l<285{deg} and |b|>15{deg} with a total exposure of 6.4Ms. The gaseous halo spectra are represented by a single-temperature plasma model in collisional ionization equilibrium. The median temperature of the observed fields is 0.26keV (3.0x10^6^K) with a typical fluctuation of ~30%. The emission measure varies by an order of magnitude and marginally correlates with the Galactic latitude. Despite the large scatter of the data, the emission measure distribution is roughly reproduced by a disk-like density distribution with a scale length of ~7kpc, a scale height of ~2kpc, and a total mass of ~5x10^7^M_{sun}_. In addition, we found that a spherical hot gas with the {beta}-model profile hardly contributes to the observed X-rays but that its total mass might reach >~10^9^M_{sun}_. Combined with indirect evidence of an extended gaseous halo from other observations, the hot gaseous halo likely consists of a dense disk-like component and a rarefied spherical component; the X-ray emissions primarily come from the former, but the mass is dominated by the latter. The disk-like component likely originates from stellar feedback in the Galactic disk due to the low scale height and the large scatter of the emission measures. The median [O/Fe] of ~0.25 shows the contribution of the core-collapse supernovae and supports the stellar feedback origin.
- ID:
- ivo://CDS.VizieR/J/A+A/602/A115
- Title:
- X-ray survey of NGC7000/IC5070
- Short Name:
- J/A+A/602/A115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first extensive X-ray study of the North-America and Pelican star-forming region (NGC7000/IC5070), with the aim of finding and characterizing the young population of this cloud. X-ray data from Chandra (four pointings) and XMM-Newton (seven pointings) were reduced and source detection algorithm applied to each image. We complement the X-ray data with optical and near-IR data from the IPHAS, UKIDSS, and 2MASS catalogs, and with other published optical and Spitzer IR data. More than 700 X-ray sources are detected, the majority of which have an optical or NIR counterpart. This allowed us to identify young stars in different stages of formation. Less than 30% of X-ray sources are identified with a previously known young star. We argue that most X-ray sources with an optical or NIR counterpart, except perhaps for a few tens at near-zero reddening, are likely candidate members of the star-forming region, on the basis of both their optical and NIR magnitudes and colors, and of X-ray properties such as spectrum hardness or flux variations. They are characterized by a wide range of extinction, and sometimes near-IR excesses, both of which prevent derivation of accurate stellar parameters. The optical color-magnitude diagram suggests ages between 1-10Myrs. The X-ray members have a very complex spatial distribution with some degree of subclustering, qualitatively similar to that of previously known members. The detailed distribution of X-ray sources relative to the objects with IR excesses identified with Spitzer is sometimes suggestive of sequential star formation, especially near the 'Gulf of Mexico' region, probably triggered by the O5 star which illuminates the whole region. We confirm that around the O5 star no enhancement in the young star density is found, in agreement with previous results. Thanks to the precision and depth of the IPHAS and UKIDSS data used, we also determine the local optical-IR reddening law, and compute an updated reddening map of the entire region.
- ID:
- ivo://CDS.VizieR/J/A+A/646/A103
- Title:
- YSO candidates in S169
- Short Name:
- J/A+A/646/A103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With the aim of studying the physical properties of Galactic IR bubbles and to explore their impact in massive star formation, we present a study of the IR bubble S169, associated with the massive star forming region IRAS 12326-6245. We used CO (2-1),^13^CO (2-1), C^18^O (2-1), HCN (3-2), and HCO^+^ (3-2) line data obtained with the APEX telescope using the on-the-fly full sampling technique to study the properties of the molecular gas in the nebula and the IRAS source. To analyze the properties and distribution of the dust, we made use of images obtained from the IRAC-GLIMPSE, Herschel, and ATLASGAL archives. The properties of the ionized gas in the nebula were studied using radio continuum and H{alpha} images obtained from the SUMSS survey and SuperCOSMOS database, respectively. In our search for stellar and protostellar objects in the region, we used point source calalogs obtained from the MSX, WISE, GLIMPSE, 2MASS, AAVSO, ASCC-2.5V3, and GAIA databases. The new APEX observations allowed us to identify three molecular components, each one associated with different regions of the nebula, namely: at -39km/s (component A), -25km/s (component B), and -17km/s (component C). Component A is shown to be the most dense and clumpy. Six molecular condensations (MC1 to MC6) were identified in this component, with MC3 (the densest and more massive one) being the molecular counterpart of IRAS 12326-6245. For this source, we estimated an H_2_ column density up to 8x10^23^cm^-2^. An LTE analysis of the high density tracer lines HCO^+^ (3-2) and HCN (3-2) on this source, assuming 50 and 150K, respectively, indicates column densities of N(HCO^+^)=(5.2+/-0.1)x10^13^cm^-2^ and N(HCN)=(1.9+/-0.5)x10^14^cm^-2^. To explain the morphology and velocity of components A, B, and C, we propose a simple model consisting of a partially complete semisphere-like structure expanding at ~12km/s. The introduction of this model has led to a discussion about the distance to both S169 and IRAS 12326-6245, which was estimated to be ~2kpc. Several candidate YSOs were identified, projected mostly onto the molecular condensations MC3, MC4, and MC5, which indicates that the star-formation process is very active at the borders of the nebula. A comparison between observable and modeled parameters was not enough to discern whether the collect-and-collapse mechanism is acting at the edge of S169. However, other processes such as radiative-driven implosion or even a combination of both mechanisms, namely, collect-and-collapse and radiative-driven implosion, could be acting simultaneously in the region.
- ID:
- ivo://CDS.VizieR/J/ApJ/830/57
- Title:
- YSO candidates in the dust bubble N10 with WISE
- Short Name:
- J/ApJ/830/57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We studied the environment of the dust bubble N10 in molecular emission. Infrared bubbles, first detected by the GLIMPSE survey at 8.0{mu}m, are ideal regions to investigate the effect of the expansion of the HII region on its surroundings and the eventual triggering of star formation at its borders. In this work, we present a multi-wavelength study of N10. This bubble is especially interesting because infrared studies of the young stellar content suggest a scenario of ongoing star formation, possibly triggered on the edge of the HII region. We carried out observations of ^12^CO(1-0) and ^13^CO(1-0) emission at PMO 13.7m toward N10. We also analyzed the IR and sub-millimeter emission on this region and compare those different tracers to obtain a detailed view of the interaction between the expanding HII region and the molecular gas. We also estimated the parameters of the denser cold dust condensation and the ionized gas inside the shell. Bright CO emission was detected and two molecular clumps were identified from which we have derived physical parameters. We also estimate the parameters for the densest cold dust condensation and for the ionized gas inside the shell. The comparison between the dynamical age of this region and the fragmentation timescale favors the "Radiation-Driven Implosion" mechanism of star formation. N10 is a case of particular interest with gas structures in a narrow frontier between the HII region and surrounding molecular material, and with a range of ages of YSOs situated in the region, indicating triggered star formation.
- ID:
- ivo://CDS.VizieR/J/ApJS/234/8
- Title:
- YSO jets from UWISH2. IV. Cygnus-X outflows
- Short Name:
- J/ApJS/234/8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have performed an unbiased search for outflows from young stars in Cygnus-X using 42deg^2^ of data from the UKIRT Widefield Infrared Survey for H_2_ (UWISH2 Survey), to identify shock-excited near-IR H_2_ emission in the 1-0 S(1) 2.122{mu}m line. We uncovered 572 outflows, of which 465 are new discoveries, increasing the number of known objects by more than 430%. This large and unbiased sample allows us to statistically determine the typical properties of outflows from young stars. We found 261 bipolar outflows, and 16% of these are parsec scale. The typical bipolar outflow is 0.45pc in length and has gaps of 0.025-0.1pc between large knots. The median luminosity in the 1-0 S(1) line is 10^-3^L_{sun}_. The bipolar flows are typically asymmetrical, with the two lobes misaligned by 5{deg}, one lobe 30% shorter than the other, and one lobe twice as bright as the other. Of the remaining outflows, 152 are single- sided and 159 are groups of extended, shock-excited H2 emission without identifiable driving sources. Half of all driving sources have sufficient WISE data to determine their evolutionary status as either protostars (80%) or classical T Tauri stars (20%). One-fifth of the driving sources are variable by more than 0.5mag in the K-band continuum over several years. Several of the newly identified outflows provide excellent targets for follow-up studies. We particularly encourage the study of the outflows and young stars identified in a bright-rimmed cloud near IRAS 20294+4255, which seems to represent a textbook example of triggered star formation.