30 research outputs found
Fabrication of Superconductor-Insulator-Superconductor Devices for Heterodyne Mixer Applications with Electron Beam Lithography
Velocity resolved [CII], [CI], and CO observations of the N159 star-forming region in the Large Magellanic Cloud: a complex velocity structure and variation of the column densities
The [CII]158um line is one of the dominant cooling lines in star-forming
active regions. The commonly assumed clumpy UV-penetrated cloud models predict
a [CII] line profile similar to that of CO. However, recent spectral-resolved
observations show that they are often very different, indicating a more complex
origin of the line emission including the dynamics of the source region. The
aim of our study is to investigate the physical properties of the star-forming
ISM in the Large Magellanic Cloud (LMC) by separating the origin of the
emission lines spatially and spectrally. In this paper, we focus on the
spectral characteristics and the origin of the emission lines, and the phases
of carbon-bearing species in the N159 star-forming region in the LMC. We mapped
a 4'x(3-4)' region in N159 in [CII]158um and [NII]205um with the GREAT on board
SOFIA, and in CO(3-2), (4-3), (6-5), 13CO(3-2), and [CI]3P1-3P0 and 3P2-3P1
with APEX. The emission of all transitions observed shows a large variation in
the line profiles across the map and between the different species. At most
positions the [CII] emission line profile is substantially wider than that of
CO and [CI]. We estimated the fraction of the [CII] integrated line emission
that cannot be fitted by the CO line profile to be 20%-50%. We derived the
relative contribution from C+, C, and CO to the column density in each velocity
bin. The contribution from C+ dominates the velocity range far from the
velocities traced by the dense molecular gas, and the region located between
the CO cores of N159 W and E. We estimate the contribution of the ionized gas
to the [CII] emission using the ratio to the [NII] emission to be < 19% to the
[CII] emission at its peak position, and <15% over the whole observed region.
Using the integrated line intensities, we present the spatial distribution of
I([CII])/I(FIR). (abridged for arXiv)Comment: 16 pages with 14 figures, accepted for publication in A&
The fine structure line deficit in S 140
We try to understand the gas heating and cooling in the S 140 star forming
region by spatially and spectrally resolving the distribution of the main
cooling lines with GREAT/SOFIA. We mapped the fine structure lines of [OI] (63
{\mu}m) and [CII] (158 {\mu}m) and the rotational transitions of CO 13-12 and
16-15 with GREAT/SOFIA and analyzed the spatial and velocity structure to
assign the emission to individual heating sources. We measure the optical depth
of the [CII] line and perform radiative transfer computations for all observed
transitions. By comparing the line intensities with the far-infrared continuum
we can assess the total cooling budget and measure the gas heating efficiency.
The main emission of fine structure lines in S 140 stems from a 8.3'' region
close to the infrared source IRS 2 that is not prominent at any other
wavelength. It can be explained by a photon-dominated region (PDR) structure
around the embedded cluster if we assume that the [OI] line intensity is
reduced by a factor seven due to self-absorption. The external cloud interface
forms a second PDR at an inclination of 80-85 degrees illuminated by an UV
field of 60 times the standard interstellar radiation field. The main radiation
source in the cloud, IRS 1, is not prominent at all in the fine structure
lines. We measure line-to-continuum cooling ratios below 10^(-4), i.e. values
lower than in any other Galactic source, rather matching the far-IR line
deficit seen in ULIRGs. In particular the low intensity of the [CII] line can
only be modeled by an extreme excitation gradient in the gas around IRS 1. We
found no explanation why IRS 1 shows no associated fine-structure line peak,
while IRS 2 does. The inner part of S 140 mimics the far-IR line deficit in
ULIRGs thereby providing a template that may lead to a future model.Comment: Accepted for publication in Astronomy & Astrophysic
SuperCam: a 64 pixel heterodyne imaging spectrometer
We report on the development of SuperCam, a 64 pixel imaging spectrometer designed for operation in the astrophysically important 870 micron atmospheric window. SuperCam will be used to answer fundamental questions about the physics and chemistry of molecular clouds in the Galaxy and their direct relation to star and planet formation. The Supercam key project is a fully sampled Galactic plane survey covering over 500 square degrees of the Galaxy in 12CO(3-2) and 13CO(3-2) with 0.3 km/s velocity resolution
SuperCam: a 64 pixel heterodyne imaging spectrometer
We report on the development of SuperCam, a 64 pixel imaging spectrometer designed for operation in the astrophysically important 870 micron atmospheric window. SuperCam will be used to answer fundamental questions about the physics and chemistry of molecular clouds in the Galaxy and their direct relation to star and planet formation. The Supercam key project is a fully sampled Galactic plane survey covering over 500 square degrees of the Galaxy in 12CO(3-2) and 13CO(3-2) with 0.3 km/s velocity resolution
Novel multiple sclerosis susceptibility loci implicated in epigenetic regulation.
We conducted a genome-wide association study (GWAS) on multiple sclerosis (MS) susceptibility in German cohorts with 4888 cases and 10,395 controls. In addition to associations within the major histocompatibility complex (MHC) region, 15 non-MHC loci reached genome-wide significance. Four of these loci are novel MS susceptibility loci. They map to the genes L3MBTL3, MAZ, ERG, and SHMT1. The lead variant at SHMT1 was replicated in an independent Sardinian cohort. Products of the genes L3MBTL3, MAZ, and ERG play important roles in immune cell regulation. SHMT1 encodes a serine hydroxymethyltransferase catalyzing the transfer of a carbon unit to the folate cycle. This reaction is required for regulation of methylation homeostasis, which is important for establishment and maintenance of epigenetic signatures. Our GWAS approach in a defined population with limited genetic substructure detected associations not found in larger, more heterogeneous cohorts, thus providing new clues regarding MS pathogenesis