8,076 research outputs found
Windows through the Dusty Disks Surrounding the Youngest Low Mass Protostellar Objects
The formation and evolution of young low mass stars are characterized by
important processes of mass loss and accretion ocurring in the innermost
regions of their placentary circumstellar disks. Because of the large
obscuration of these disks at optical and infrared wavelengths in the early
protostellar stages (Class 0 Sources), they were previously detected only at
radio wavelengths using interferometric techniques. We have detected with the
Infrared Space Observatory (ISO) the mid-infrared emission associated with the
Class 0 protostar VLA1 in the HH1-2 region located in the Orion nebula. The
emission arises in the three wavelength windows at 5.3, 6.6 and 7.5 micras
where the absorption due to ices and silicates has a local minimum that exposes
the central parts of the youngest protostellar systems to mid-infrared
investigations. The mid-infrared emission arises from a central source with 4
AU diameter at an averaged temperature of 700 K, deeply embedded in a dense
region with a visual extinction of Av=80-100mag.Comment: The article is here and on pres
The ultraviolet spectrum of HH 24A and its relation to optical spectra
The spectrum of the brightest part (HH 24A) of the complex Herbig-Haro object HH 24 in the short wavelength UV range was studied. The object is of special interest since it is known that in the optical range the continuum is due to dust scattered light originating in a young stellar object while the shock excited emission lines are formed in HH 24A itself. The spectrum shows only a continuum or a quasi-continuum and is not comparable to that of the typical high excitation object like HH1 or HH2 nor to that of a low excitation object like HH3 or HH47
The infrared and molecular environment surrounding the Wolf-Rayet star WR130
We present a study of the molecular CO gas and mid/far infrared radiation
arising from the environment surrounding the Wolf-Rayet (W-R) star 130. We use
the multi-wavelength data to analyze the properties of the dense gas and dust,
and its possible spatial correlation with that of Young Stellar Objects (YSOs).
We use CO J=1-0 data from the FCRAO survey as tracer of the molecular gas, and
mid/far infrared data from the recent WISE and Herschel space surveys to study
the dust continuum radiation and to identify a population of associated
candidate YSOs. The spatial distribution of the molecular gas shows a ring-like
structure very similar to that observed in the HI gas, and over the same
velocity interval. The relative spatial distribution of the HI and CO
components is consistent with a photo-dissociation region. We have identified
and characterized four main and distinct molecular clouds that create this
structure. Cold dust is coincident with the dense gas shown in the CO
measurements. We have found several cYSOs that lie along the regions with the
highest gas column density, and suggest that they are spatially correlated with
the shell. These are indicative of regions of star formation induced by the
strong wind and ionization of the WR star.Comment: 15 pages, 12 figures, 6 Tables. Accepted for publication in MNRA
Preconception care for infertile couples: nurses' and midwives' roles in promoting better maternal and birth outcomes
Introduction Preconception care promotes better maternal outcomes, may assist in preventing birth defects and improves fertility awareness among healthy childbearing couples. Yet the significance of preconception care for infertile couples is undeveloped area of practice in Europe.
Aim We discuss the importance of nurses and midwives in providing preconception care to infertile couples in the United Kingdom and Spain.
Design Discursive paper
Method A comparison of different midwifery and nursing approaches to preconception care for infertile couples in two European countries.
Findings At present infertile couples’ needs for preconception care are not routinely identified or understood. There is an opportunity for these needs to be considered and identified by nurses at the time of investigation for infertility or when planning pregnancy with assisted conception.
Conclusions We argue that by providing preconception care, nurses and midwives have an opportunity to deliver important advice to infertile couples in both primary care and specialist infertility services
A Catalog of MIPSGAL Disk and Ring Sources
We present a catalog of 416 extended, resolved, disk- and ring-like objects
as detected in the MIPSGAL 24 micron survey of the Galactic plane. This catalog
is the result of a search in the MIPSGAL image data for generally circularly
symmetric, extended "bubbles" without prior knowledge or expectation of their
physical nature. Most of the objects have no extended counterpart at 8 or 70
micron, with less than 20% detections at each wavelength. For the 54 objects
with central point sources, the sources are nearly always seen in all IRAC
bands. About 70 objects (16%) have been previously identified, with another 35
listed as IRAS sources. Among the identified objects, those with central
sources are mostly listed as emission-line stars, but with other source types
including supernova remnants, luminous blue variables, and planetary nebulae.
The 57 identified objects (of 362) without central sources are nearly all PNe
(~90%).which suggests that a large fraction of the 300+ unidentified objects in
this category are also PNe. These identifications suggest that this is
primarily a catalog of evolved stars. Also included in the catalog are two
filamentary objects that are almost certainly SNRs, and ten unusual compact
extended objects discovered in the search. Two of these show remarkable spiral
structure at both 8 and 24 micron. These are likely background galaxies
previously hidden by the intervening Galactic plane
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