3,666 research outputs found
A catalog of known Galactic K-M stars of class I, candidate RSGs, in Gaia DR2
We investigate individual distances and luminosities of a sample of 889
nearby candidate red supergiants with reliable parallaxes (plx/plxerr > 4 and
RUWE < 2.7) from Gaia DR2. The sample was extracted from the historical
compilation of spectroscopically derived spectral types by Skiff (2014), and
consists of K-M stars that are listed with class I at least once. The sample
includes well-known red supergiants from Humphreys (1978), Elias et al. (1985),
Jura and Kleinmann (1990), and Levesque et al. (2005). Infrared and optical
measurements from the 2MASS, CIO, MSX, WISE, MIPSGAL, GLIMPSE, and NOMAD
catalogs allow us to estimate the stellar bolometric magnitudes. We analyze the
stars in the luminosity versus effective temperature plane and confirm that 43
sources are highly-probably red supergiants with Mbol<-7.1 mag. 43% of the
sample is made of stars with masses > 7 Msun. Another 30% of the sample
consists of giant stars.Comment: 14 pages, 7 Figures, accepted by ApJ. See
https://somethingaboutrsgstars.wordpress.com/ or
http://staff.ustc.edu.cn/~messine
Detections of massive stars in the cluster MCM2005b77, in the star-forming regions GRS G331.3400.36 (S62) and GRS G337.9200.48 (S36)
Large infrared and millimeter wavelength surveys of the Galactic plane have
unveiled more than 600 new bubble HII regions and more than 3000 candidate star
clusters. We present a study of the candidate clusters MCM2005b72, DBS2003-157,
DBS2003-172, and MCM2005b77, based on near-infrared spectroscopy taken with
SofI on the NTT and infrared photometry from the 2MASS, VVV, and GLIMPSE
surveys. We find that (1) MCM2005b72 and DBS2003-157 are subregions of the same
star-forming region, HII GRS G331.34-00.36 (bubble S62). MCM2005b72 coincides
with the central part of this HII region, while DBS2003-157 is a bright
mid-infrared knot of the S62 shell. We detected two O-type stars at extinction
\Aks=1.0-1.3 mag. Their spectrophotometric properties are consistent with the
near-kinematic distance to GRS G331.34-00.36 of 3.9pm0.3 kpc. (2) DBS2003-172
coincides with a bright mid-infrared knot in the S36 shell (GRS G337.92-00.48),
where we detected a pair of candidate He I stars embedded in a small cometary
nebula. (3) The stellar cluster MCM2005b77 is rich in B-type stars, has an
average Aks of 0.91 mag, and is adjacent to the HII region IRAS 16137-5025. The
average spectrophotometric distance of kpc matches the
near-kinematic distance to IRAS 16137-5025 of 5.2pm0.1 kpc.Comment: 22 pages, 11 Figures, ApJ accepte
Diagnostic imaging and CEUS findings in a rare case of Desmoid-type fibromatosis. A case report
Desmoid-type fibromatosis (DF), also known as aggressive fibromatosis, is a locally aggressive benign fibroblastic neoplasm that can infiltrate or recur but cannot metastasize. It is rare, with an estimated annual incidence of two to four new cases per million people. Most DFs occur sporadically, but it may also be associated with the hereditary syndrome familial adenomatous polyposis. Treatment is necessary when the disease is symptomatic, especially in case of compression of critical structures. When possible, surgical resection is the treatment of choice; however, recurrence is common. Due to the high rate of recurrence, imaging plays an important role not only in diagnosis, but also in the management of DF. Although there are a number of studies describing CT and MRI findings of DF, there is no description of contrast-enhanced ultrasound findings
HST/NICMOS observations of the GLIMPSE9 stellar cluster
We present HST/NICMOS photometry, and low-resolution K-band spectra of the
GLIMPSE9 stellar cluster. The newly obtained color-magnitude diagram shows a
cluster sequence with H-Ks =1 mag, indicating an interstellar extinction
Aks=1.6\pm0.2 mag. The spectra of the three brightest stars show deep CO
band-heads, which indicate red supergiants with spectral type M1-M2. Two 09-B2
supergiants are also identified, which yield a spectrophotometric distance of
4.2\pm0.4 kpc. Presuming that the population is coeval, we derive an age
between 15 and 27 Myr, and a total cluster mass of 1600\pm400 Msun, integrated
down to 1 Msun. In the vicinity of GLIMPSE9 are several HII regions and SNRs,
all of which (including GLIMPSE 9) are probably associated with a giant
molecular cloud (GMC) in the inner galaxy. GLIMPSE9 probably represents one
episode of massive star formation in this GMC. We have identified several other
candidate stellar clusters of the same complex.Comment: 13 pages, 14 figures. accepted for publication in ApJ. A version with
high-resolution figures can be found at the following location
ftp://ftp.rssd.esa.int/pub/mmessine/ms.pdf New version with updated
reference
Massive stars in the Cl 1813-178 Cluster. An episode of massive star formation in the W33 complex
Young massive (M >10^4 Msun) stellar clusters are a good laboratory to study
the evolution of massive stars. Only a dozen of such clusters are known in the
Galaxy. Here we report about a new young massive stellar cluster in the Milky
Way. Near-infrared medium-resolution spectroscopy with UIST on the UKIRT
telescope and NIRSPEC on the Keck telescope, and X-ray observations with the
Chandra and XMM satellites, of the Cl 1813-178 cluster confirm a large number
of massive stars. We detected 1 red supergiant, 2 Wolf-Rayet stars, 1 candidate
luminous blue variable, 2 OIf, and 19 OB stars. Among the latter, twelve are
likely supergiants, four giants, and the faintest three dwarf stars. We
detected post-main sequence stars with masses between 25 and 100 Msun. A
population with age of 4-4.5 Myr and a mass of ~10000 Msun can reproduce such a
mixture of massive evolved stars. This massive stellar cluster is the first
detection of a cluster in the W33 complex. Six supernova remnants and several
other candidate clusters are found in the direction of the same complex.Comment: 11 Figures. Accepted for publication in Ap
A comparative wordlist for the languages of The Gran Chaco, South America
Home to more than twenty indigenous languages belonging to six linguistic families, the Gran Chaco has raised the interest of many linguists from different backgrounds. While some have focused on finding deeper genetic relations between different language groups, others have looked into similarities from the perspective of areal linguistics. In order to contribute to further research of areal and genetic features among these languages, we have compiled a comparative wordlist consisting of translational equivalents for 326 concepts - representing basic and ethnobiological vocabulary - for 26 language varieties. Since the data were standardized in various ways, they can be analyzed both quantitatively and qualitatively. In order to illustrate this in detail, we have carried out an initial computer-assisted analysis of parts of the data by searching for shared lexicosemantic patterns resulting from structural rather than direct borrowings.Fil: Brid, Nicolás. Universidad de Buenos Aires; ArgentinaFil: Messineo, Maria Cristina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: List, Johann-Mattis. Institut Max Planck for Evolutionary Anthropology; Alemani
Near-infrared spectroscopy of candidate red supergiant stars in clusters
Clear identifications of Galactic young stellar clusters farther than a few
kpc from the Sun are rare, despite the large number of candidate clusters. We
aim to improve the selection of candidate clusters rich in massive stars with a
multiwavelength analysis of photometric Galactic data that range from optical
to mid-infrared wavelengths. We present a photometric and spectroscopic
analysis of five candidate stellar clusters, which were selected as
overdensities with bright stars (Ks < 7 mag) in GLIMPSE and 2MASS images. A
total of 48 infrared spectra were obtained. The combination of photometry and
spectroscopy yielded six new red supergiant stars with masses from 10 Msun to
15 Msun. Two red supergiants are located at Galactic coordinates
(l,b)=(16.7deg,-0.63deg) and at a distance of about ~3.9 kpc; four other red
supergiants are members of a cluster at Galactic coordinates
(l,b)=(49.3deg,+0.72deg) and at a distance of ~7.0 kpc. Spectroscopic analysis
of the brightest stars of detected overdensities and studies of interstellar
extinction along their line of sights are fundamental to distinguish regions of
low extinction from actual stellar clusters. The census of young star clusters
containing red supergiants is incomplete; in the existing all-sky near-infrared
surveys, they can be identified as overdensities of bright stars with infrared
color-magnitude diagrams characterized by gaps.Comment: 16 pages, 10 figures, accepted to A&A 201
Massive Stars in Molecular Clouds Rich in High-energy Sources: The Bridge of G332.809-0.132 and CS 78 in NGC 6334
Detections of massive stars in the direction of the H II region CS 78 in NGC
6334 and of G332.809-0.132 are here presented. The region covered by the
G332.809-0.132 complex coincides with the RCW 103 stellar association. In its
core (40' in radius), approximately 110 OB candidate stars (Ks < 10 mag and 0.4
< AKs < 1.6 mag) were identified using 2MASS, DENIS, and GLIMPSE data. This
number of OB stars accounts for more than 50% of the observed number of Lyman
continuum photons from this region. Medium-resolution K-band spectra were
obtained for seven early types, including one WN 8 star and one Ofpe/WN 9 star;
the latter is located near the RCW 103 remnant and its luminosity is consistent
with a distance of about 3 kpc. The area analyzed encloses 9 of the 34 OB stars
previously known in RCW 103, as well as IRAS 16115-5044, which we reclassify as
a candidate luminous blue variable. The line of sight is particularly
interesting, crossing three spiral arms; a molecular cloud at -50 (with RCW 103
in the Scutum-Crux arm) and another at -90 km s-1 (in the Norma arm) are
detected, both rich in massive stars and supernova remnants. We also report the
detection of a B supergiant as the main ionizing source of CS 78, 2MASS
J17213513-3532415. Medium-resolution H and K band spectra display H I and He I
lines, as well as Fe II lines. By assuming a distance of 1.35 kpc, we estimate
a bolometric magnitude of -6.16, which is typical of supergiants.Comment: 44 pages, 15 figure
An unusual location of hand, foot and mouth disease
Hand, foot, and mouth disease (HFMD) is a childhood febrile disease. Oral lesions and papulovesicular lesions on the hands and feet are the clinical signs of the disease. In our case, a 17-year-old boy presented to the emergency department, where he was diagnosed with HFMD. After 6days, he felt intense pain in his right testicle, and therefore an ultrasound (US) examination was performed. US detected a hypoechoic mass-like area in the right testis. Viral etiology was suspected, and no therapy was prescribed. After a little more than 3months, US examination showed a reduced lesion size. Viral epididymo-orchitis should be suspected in young men with a recent history of HFMD and testicular pain
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