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- ID:
- ivo://CDS.VizieR/J/ApJ/635/560
- Title:
- New star clusters discovered in the GLIMPSE survey
- Short Name:
- J/ApJ/635/560
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A systematic and automated search of the extensive GLIMPSE (Galactic Legacy Infrared Mid-Plane Survey Extraordinaire) mid-infrared survey data of the inner Galaxy was carried out to uncover new star clusters. This search has yielded 59 new clusters. Using our automated search algorithm, these clusters were identified as significant localized overdensities in the GLIMPSE point-source catalog (GLMC) and archive (GLMA). Subsequent visual inspection of the GLIMPSE image mosaics confirmed the existence of these clusters plus an additional 33 heavily embedded clusters missed by our detection algorithm, for a total of 92 newly discovered clusters.
- ID:
- ivo://CDS.VizieR/J/ApJ/856/152
- Title:
- New star clusters in the central plane region
- Short Name:
- J/ApJ/856/152
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of new star clusters in the central plane region (|l|<30{deg} and |b|<6{deg}) of the Milky Way. In order to overcome the extinction problem and the spatial limit of previous surveys, we use the Wide-field Infrared Survey Explorer (WISE) data to find clusters. We also use other infrared survey data in the archive for additional analysis. We find 923 new clusters, of which 202 clusters are embedded clusters. These clusters are concentrated toward the Galactic plane and show a symmetric distribution with respect to the Galactic latitude. The embedded clusters show a stronger concentration to the Galactic plane than the nonembedded clusters. The new clusters are found more in the first Galactic quadrant, while previously known clusters are found more in the fourth Galactic quadrant. The spatial distribution of the combined sample of known clusters and new clusters is approximately symmetric with respect to the Galactic longitude. We estimate reddenings, distances, and relative ages of the 15 class A clusters using theoretical isochrones. Ten of them are relatively old (age >800Myr) and five are young (age ~4Myr).
- ID:
- ivo://CDS.VizieR/J/AJ/142/77
- Title:
- New T dwarfs identified in Pan-STARRS 1
- Short Name:
- J/AJ/142/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A complete well-defined sample of ultracool dwarfs is one of the key science programs of the Pan-STARRS 1 optical survey telescope (PS1). Here we combine PS1 commissioning data with the Two Micron All Sky Survey (2MASS) to conduct a proper motion search (0.1-2.0"/yr) for nearby T dwarfs, using optical+near-IR colors to select objects for spectroscopic follow-up. The addition of sensitive far-red optical imaging from PS1 enables discovery of nearby ultracool dwarfs that cannot be identified from 2MASS data alone. We have searched 3700deg^2^ of PS1 y-band (0.95-1.03um) data to y~19.5mag (AB) and J~16.5mag (Vega) and discovered four previously unknown bright T dwarfs. Three of the objects (with spectral types T1.5, T2, and T3.5) have photometric distances within 25pc and were missed by previous 2MASS searches due to more restrictive color selection criteria. The fourth object (spectral type T4.5) is more distant than 25pc and is only a single-band detection in 2MASS. We also examine the potential for completing the census of nearby ultracool objects with the PS1 3{PI} survey.
- ID:
- ivo://CDS.VizieR/J/A+A/497/619
- Title:
- New ultra-cool dwarfs from SDSS and 2MASS
- Short Name:
- J/A+A/497/619
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We try to identify ultra-cool dwarfs from the seventh Data Release of the Sloan Digital Sky Survey (SDSS DR7) with SDSS i-z and r-z colors. We also obtain proper motion data from SDSS, 2MASS, and UKIDSS and improve spectral typing from SDSS and 2MASS photometric colors.
- ID:
- ivo://CDS.VizieR/J/ApJ/554/803
- Title:
- New VLA Sky Survey (NVSS) Cat of IRAS 2 Jy Galaxies
- Short Name:
- J/ApJ/554/803
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The radio counterparts to the IRAS Redshift Survey galaxies are identified in the NRAO VLA Sky Survey (NVSS) catalog. Our new catalog of the IR flux-limited (>2 Jy at 60 micron) complete sample of 1809 galaxies lists accurate radio positions, redshifts, and 1.4 GHz radio and IRAS flux densities and luminosities.
- ID:
- ivo://CDS.VizieR/J/MNRAS/452/1523
- Title:
- New young stellar cluster towards IRAS 04186+5143
- Short Name:
- J/MNRAS/452/1523
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of a new young stellar cluster in the outer Galaxy located at the position of an IRAS Point Source Catalog source that has been previously misidentified as an external galaxy. The cluster is seen in our near-infrared imaging towards IRAS 04186+5143 and in archive Spitzer images confirming the young stellar nature of the sources detected. There is also evidence of subclustering seen in the spatial distributions of young stars and of gas and dust. Near- and mid-infrared photometry indicates that the stars exhibit colours compatible with reddening by interstellar and circumstellar dust and are likely to be low- and intermediate-mass young stellar objects (YSOs) with a large proportion of Class I YSOs. Ammonia and CO lines were detected, with the CO emission well centred near the position of the richest part of the cluster. The velocity of the CO and NH3 lines indicates that the gas is Galactic and located at a distance of about 5.5kpc, in the outer Galaxy. Herschel data of this region characterize the dust environment of this molecular cloud core where the young cluster is embedded. We derive masses, luminosities, and temperatures of the molecular clumps where the young stars reside and discuss their evolutionary stages.
- ID:
- ivo://CDS.VizieR/J/A+A/605/A85
- Title:
- NGC 3293 Chandra X-ray observation
- Short Name:
- J/A+A/605/A85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 3293 is a young stellar cluster at the northwestern periphery of the Carina Nebula Complex that remained poorly explored until now. We want to characterize the stellar population of NGC 3293 in order to evaluate key parameters of the cluster population like the age and the mass function, and to test claims of an abnormal IMF and a deficit of M<=2.5M_{sun}_ stars. WWe performed a deep (70 ksec) X-ray observation of NGC 3293 with Chandra and detected 1026 individual X-ray point sources. These X-ray data directly probe the low-mass (M<=2M_{sun}_) stellar population by means of the strong X-ray emission of young low-mass stars. We identify counterparts for 74% of the X-ray sources in our deep near-infrared images. Our data clearly show that NGC 3293 hosts a large population of ~solar-mass stars, refuting claims of a lack of M<=2.5M_{sun}_ stars. The analysis of the color-magnitude diagram suggests an age of ~8-10Myr for the low-mass population of the cluster. There are at least 511 X-ray detected stars with color-magnitude positions that are consistent with young stellar members within 7 arcmin from the cluster center. The number ratio of X-ray detected stars in the [1-2]M_{sun}_ range versus the M<=5M_{sun}_ stars (known from optical spectroscopy) is well consistent with the expectation from a normal field initial mass function. Most of the early B-type stars and ~20% of the later B-type stars are detected as X-ray sources. Our data shows that NGC 3293 is one of the most populous stellar clusters in the entire Carina Nebula Complex (only excelled by Tr 14, and very similar to Tr 16 and Tr 15). The cluster has probably harbored several O-type stars, the supernova explosions of which may have had an important impact on the early evolution of the Carina Nebula Complex.
- ID:
- ivo://CDS.VizieR/J/A+A/599/A9
- Title:
- NGC 4214 [CII] line profile
- Short Name:
- J/A+A/599/A9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used SOFIA/GREAT [CII] 158um observations as well as HI data from THINGS and CO(2-1) data from HERACLES to decompose the spectrally resolved [CII] line profiles in NGC4124 into components associated with neutral atomic and molecular gas. We infer gas masses traced by [CII] under different ISM conditions. We find that the molecular gas mass is dominated by CO-dark gas and that we can only assign 9 percent of [CII] intensity to the cold neutral medium.
- ID:
- ivo://CDS.VizieR/J/A+A/575/A17
- Title:
- NGC 891 Herschel PACS and SPIRE spectroscopy
- Short Name:
- J/A+A/575/A17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Herschel PACS and SPIRE spectroscopy of the most important far- infrared cooling lines in the nearby edge-on spiral galaxy, NGC 891: the [CII] 158, [NII] 122, 205, [OI] 63, 145, and [OIII] 88 micron lines. We find that the photoelectric heating efficiency of the gas varies from a mean of 3.5x10^-3^ in the centre up to 8x10^-3^ at increasing radial and vertical distances in the disc. We compare the observed flux of the FIR cooling lines and total IR emission with the predicted flux from a PDR model to determine the gas density, surface temperature and the strength of the incident far-ultraviolet (FUV) radiation field, G_0_. Resolving details on physical scales of ~0.6kpc, a pixel-by-pixel analysis reveals that the majority of the PDRs in NGC 891's disc have hydrogen densities of 1<log(n/cm^-3^)<3.5 experiencing an incident FUV radiation field with strengths of 1.7<logG_0_<3. Although these values we derive for most of the disc are consistent with the gas properties found in PDRs in the spiral arms and inter-arm regions of M51, observed radial trends in n and G_0_ appear to be sensitive to varying optical thickness in the lines, demonstrating the importance of accurately accounting for optical depth effects when interpreting observations of high inclination systems. With an empirical relationship between the MIPS 24 micron and [NII] 205 micron emission, we estimate an enhancement of the FUV radiation field strength in the far north-eastern side of the disc.
