3,492 research outputs found
Alien Registration- Downes, Daniel K. (Portland, Cumberland County)
https://digitalmaine.com/alien_docs/24111/thumbnail.jp
First redshift determination of an optically/UV faint submillimeter galaxy using CO emission lines
We report the redshift of a distant, highly obscured submm galaxy (SMG),
based entirely on the detection of its CO line emission. We have used the newly
commissioned Eight-MIxer Receiver (EMIR) at the IRAM 30m telescope, with its 8
GHz of instantaneous dual-polarization bandwidth, to search the 3-mm
atmospheric window for CO emission from SMMJ14009+0252, a bright SMG detected
in the SCUBA Lens Survey. A detection of the CO(3--2) line in the 3-mm window
was confirmed via observations of CO(5--4) in the 2-mm window. Both lines
constrain the redshift of SMMJ14009+0252 to z=2.9344, with high precision (dz=2
10^{-4}). Such observations will become routine in determining redshifts in the
era of the Atacama Large Millimeter/submillimeter Array (ALMA).Comment: 5 pages, 3 figures, accepted by ApJ
2015 Green Electricity Guide Methodology and Results
The Green Electricity Guide helps to inform Australians about which electricity retailers are really as ‘green’ as they say they are. It is the only independent analysis and ranking of the environmental performance of all electricity retailers around Australia. It is an important source of information for consumers keen to support retailers who align with their values. In 2014 the first edition of the online Guide was produced by TEC and Greenpeace, using earlier ISF research as one of main the inputs to the ranking criteria. The Guide ranked 20 retailers against 7 criteria and has been visited by over 100,000 people. In 2015, ISF was contracted to update the Guide's methodology and rankings. The cost of the work was partly funded by an Advocacy grant from Energy Consumers Australia. In addition, ISF, TEC and Choice all contributed in-kind support to the project. ISF reviewed the 2014 Guide criteria and rankings, and then conducted background research to identify additional criteria and sub-criteria to expand the 2015 Guide to more comprehensively assess the 'green' credentials of Australia's electricity retailers. ISF developed a survey for retailers to capture the required information for the rankings. Information provided by retailers was then supplemented by and verified against desktop research of company websites, company reports and public reports conducted in September 2015. Each retailer's data was assessed and scored, to determine a final score and ranking for 2015. The rankings are available online at www.greenelectricityguide.com.a
Dense Molecular Gas and the Role of Star Formation in the Host Galaxies of Quasi-Stellar Objects
New millimeter-wave CO and HCN observations of the host galaxies of
infrared-excess Palomar Green quasi-stellar objects (PG QSOs) previously
detected in CO are presented. These observations are designed to assess the
validity of using the infrared luminosity to estimate star formation rates of
luminous AGN by determining the relative significance of dust-heating by young,
massive stars and active galactic nuclei (AGN) in QSO hosts and IRAS galaxies
with warm, AGN-like infrared colors. The HCN data show the PG QSO host IZw1 and
most of the warm IRAS galaxies to have high L_IR / L'_HCN (>1600) relative to
the cool IRAS galaxy population for which the median L_IR / L'_HCN ~
890(+440,-470). If the assumption is made that the infrared emission from cool
IRAS galaxies is reprocessed light from embedded star-forming regions, then
high values of L_IR / L'_HCN are likely the result of dust heating by the AGN.
Further, if the median ratio of L'_HCN / L'_CO ~ 0.06 observed for Seyfert
galaxies and IZw1 is applied to the PG QSOs not detected in HCN, then the
derived L_IR / L'_HCN correspond to a stellar contribution to the production of
L_IR of ~ 7-39%, and star formation rates ~ 2-37 M_sun/yr are derived for the
QSO hosts. Alternatively, if the far-infrared is adopted as the star formation
component of the total infrared in cool galaxies, the stellar contributions in
QSO hosts to their L_FIR are up to 35% higher than the percentages derived for
L_IR. This raises the possibility that the L_FIR in several of the PG QSO
hosts, including IZw1, could be due entirely to dust heated by young, massive
stars. Finally, there is no evidence that the global HCN emission is enhanced
relative to CO in galaxies hosting luminous AGN.Comment: LaTex, 31 pages, including 9 postscript figures, AJ, in press
(December 2006
The faint counterparts of MAMBO mm sources near the NTT Deep Field
We discuss identifications for 18 sources from our MAMBO 1.2mm survey of the
region surrounding the NTT Deep Field. We have obtained accurate positions from
Very Large Array 1.4GHz interferometry and in a few cases IRAM mm
interferometry, and have also made deep BVRIzJK imaging at ESO. We find
thirteen 1.2mm sources associated with optical/near-infrared objects in the
magnitude range K=19.0 to 22.5, while five are blank fields at K>22. The median
redshift of the radio-identified mm sources is ~2.6 from the radio/mm
estimator, and the median optical/near-infrared photometric redshifts for the
objects with counterparts ~2.1. This suggests that those radio-identified mm
sources without optical/near-infrared counterparts tend to lie at higher
redshifts than those with optical/near-infrared counterparts. Compared to
published identifications of objects from 850micron surveys of similar depth,
the median K and I magnitudes of our counterparts are roughly two magnitudes
fainter and the dispersion of I-K colors is less. Real differences in the
median redshifts, residual mis-identifications with bright objects, cosmic
variance, and small number statistics are likely to contribute to this
significant difference, which also affects redshift measurement strategies. We
discuss basic properties of the near-infrared/(sub)mm/radio spectral energy
distributions of our galaxies and of interferometrically identified submm
sources from the literature. From a comparison with submm objects with
CO-confirmed spectroscopic redshifts we argue that roughly two thirds of the
(sub)mm galaxies are at z>~2.5. This fraction is probably larger when including
sources without radio counterparts. (abridged)Comment: 45 pages, 9 figures. Accepted by ApJ. The resolution of figures 2 and
3 has been degraded. A higher quality pdf version of this paper is available
at http://www.mpe.mpg.de/~dannerb
Astronomy: Starbursts near and far
Observations of intensely bright star-forming galaxies both close by and in
the distant Universe at first glance seem to emphasize their similarity. But
look a little closer, and differences emerge.Comment: 6 pages including 1 figur
Galaxy Cluster Scaling Relations between Bolocam Sunyaev-Zel'dovich Effect and Chandra X-ray Measurements
We present scaling relations between the integrated Sunyaev-Zel'dovich Effect
(SZE) signal, , its X-ray analogue, , and total mass, , for the 45 galaxy clusters in
the Bolocam X-ray-SZ (BOXSZ) sample. All parameters are integrated within
. values are measured using SZE data collected with
Bolocam, operating at 140 GHz at the Caltech Submillimeter Observatory (CSO).
The temperature, , and mass, , of the intracluster
medium are determined using X-ray data collected with Chandra, and is derived from assuming a constant gas mass fraction. Our
analysis accounts for several potential sources of bias, including: selection
effects, contamination from radio point sources, and the loss of SZE signal due
to noise filtering and beam-smoothing effects. We measure the
-- scaling to have a power-law index of , and
a fractional intrinsic scatter in of at fixed , both of which are consistent with previous analyses. We also measure the
scaling between and , finding a power-law index of
and a fractional intrinsic scatter in at fixed mass of
. While recent SZE scaling relations using X-ray mass proxies have
found power-law indices consistent with the self-similar prediction of 5/3, our
measurement stands apart by differing from the self-similar prediction by
approximately 5. Given the good agreement between the measured
-- scalings, much of this discrepancy appears to be caused
by differences in the calibration of the X-ray mass proxies adopted for each
particular analysis.Comment: 31 pages, 15 figures, accepted by ApJ 04/11/2015. This version is
appreciably different from the original submission: it includes an entirely
new appendix, extended discussion, and much of the material has been
reorganize
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