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Bothrops asper (Terciopelo) scavenging behavior
This is the final version of the article. It first appeared from Society for the Study of Amphibians and Reptiles via https://www.zenscientist.com/index.php/pdflibrary2/func-finishdown/129/This research was sponsored by the Gates Cambridge Trust
Expanded VLA Detection of 36.2 GHz Class I Methanol Masers in Sagittarius A
We report on the interferometric detection of 36.2 GHz Class I methanol
emission with the new 27-40 GHz Ka band receivers available on the Expanded
Very Large Array (EVLA). The brightness temperatures of the interferometric 36
GHz detections unambiguously indicate for the first time that the emission is
maser emission. The 36 GHz methanol masers are not co-spatial with 1720 MHz OH
masers, indicating that the two species trace different shocks. The 36 GHz and
44 GHz methanol masers, which both are collisionally pumped, do not necessarily
co-exist and may trace different methanol gas. The methanol masers seem
correlated with NH_3(3,3) density peaks. We favor an explanation in which the
36 GHz Class I methanol masers outline regions of cloud-cloud collisions,
perhaps just before the onset of the formation of individual massive stars.
The transition of the Very Large Array (VLA) to the EVLA is well under way,
and these detections demonstrate the bright future of this completely renewed
instrument.Comment: accepted to ApJ Letter
The BOSS Emission-Line Lens Survey. III. : Strong Lensing of Ly Emitters by Individual Galaxies
We introduce the Baryon Oscillation Spectroscopic Survey (BOSS) Emission-Line
Lens Survey (BELLS) for GALaxy-Ly EmitteR sYstems (BELLS GALLERY)
Survey, which is a Hubble Space Telescope program to image a sample of
galaxy-scale strong gravitational lens candidate systems with high-redshift
Ly emitters (LAEs) as the background sources. The goal of the BELLS
GALLERY Survey is to illuminate dark substructures in galaxy-scale halos by
exploiting the small-scale clumpiness of rest-frame far-UV emission in lensed
LAEs, and to thereby constrain the slope and normalization of the
substructure-mass function. In this paper, we describe in detail the
spectroscopic strong-lens selection technique, which is based on methods
adopted in the previous Sloan Lens ACS (SLACS) Survey, BELLS, and SLACS for the
Masses Survey. We present the BELLS GALLERY sample of the 21 highest-quality
galaxy--LAE candidates selected from galaxy spectra
in the BOSS of the Sloan Digital Sky Survey III. These systems consist of
massive galaxies at redshifts of approximately 0.5 strongly lensing LAEs at
redshifts from 2--3. The compact nature of LAEs makes them an ideal probe of
dark substructures, with a substructure-mass sensitivity that is unprecedented
in other optical strong-lens samples. The magnification effect from lensing
will also reveal the structure of LAEs below 100 pc scales, providing a
detailed look at the sites of the most concentrated unobscured star formation
in the universe. The source code used for candidate selection is available for
download as a part of this release.Comment: 14 pages, 5 figures, accepted for publication in the ApJ (ApJ, 824,
86). Minor edits to match the ApJ published versio
X-ray Surface Brightness Profiles of Active Galactic Nuclei in the Extended Groth Strip: Implications for AGN Feedback
Using data from the All Wavelength Extended Groth Strip International Survey
(AEGIS) we statistically detect the extended X-ray emission in the interstellar
medium (ISM)/intra-cluster medium (ICM) in both active and normal galaxies at
0.3 <= z <= 1.3. For both active galactic nuclei (AGN) host galaxy and normal
galaxy samples that are matched in restframe color, luminosity, and redshift
distribution, we tentatively detect excess X-ray emission at scales of 1--10
arcsec at a few sigma significance in the surface brightness profiles. The
exact significance of this detection is sensitive to the true characterization
of Chandra's point spread function. The observed excess in the surface
brightness profiles is suggestive of lower extended emission in AGN hosts
compared to normal galaxies. This is qualitatively similar to theoretical
predictions of the X-ray surface brightness profile from AGN feedback models,
where feedback from AGN is likely to evacuate the gas from the center of the
galaxy/cluster. We propose that AGN that are intrinsically under-luminous in
X-rays, but have equivalent bolometric luminosities to our sources will be the
ideal sample to study more robustly the effect of AGN feedback on diffuse
ISM/ICM gas.Comment: Accepted in PAS
Gas infall towards Sgr A* from the clumpy circumnuclear disk
We present the first large-scale mosaic performed with the Submillimeter
Array (SMA) in the Galactic center. We have produced a 25-pointing mosaic,
covering a ~2' x 2' area around Sgr A*. We have detected emission from two
high-density molecular tracers, HCN(4-3) and CS(7-6), the latter never before
reported in this region. The data have an angular resolution of 4.6" x 3.1",
and the spectral window coverage is from -180 km/s to 1490 km/s for HCN(4-3)
and from -1605 km/s to 129 km/s for CS(7-6). Both molecular tracers present a
very clumpy distribution along the circumnuclear disk (CND), and are detected
with a high signal-to-noise ratio in the southern part of the CND, while they
are weaker towards the northern part. Assuming that the clumps are as close to
the Galactic center as their projected distances, they are still dense enough
to be gravitationally stable against the tidal shear produced by the
supermassive black hole. Therefore, the CND is a non-transient structure. This
geometrical distribution of both tracers suggests that the southern part of the
CND is denser than the northern part. Also, by comparing the HCN(4-3) results
with HCN(1-0) results we can see that the northern and the southern parts of
the CND have different excitation levels, with the southern part warmer than
the northern. Finally, we compare our results with those obtained with the
detection of NH3, which traces the warmer and less dense material detected in
the inner cavity of the CND. We suggest that we are detecting the origin point
where a portion of the CND becomes destabilized and approaches the dynamical
center of the Milky Way, possibly being impacted by the southern streamer and
heated on its way inwards.Comment: 35 pages, 25 figures, 2 tables, accepted for publication in ApJ,
emulate-apj styl
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