1,442 research outputs found
WOULD PEOPLE RATHER PAY TAXES OR TRADE TAXES TO PAY FOR ENVIRONMENTAL GOODS? A GROUND WATER QUALITY CASE
The potential sensitivity of environmental resource valuation to payment vehicles is of interest to researchers and decision-makers involved in estimating and applying these numbers. A conceptual model is developed which provides insight into how the different payment vehicles of a special tax and a tax reallocation affects the willingness to pay (WTP) for environmental goods. Hypothesis testing using contingent valuation data suggests WTP with a tax reallocation is higher than WTP with a special tax for ground water quality protection in Georgia and Maine.Environmental Economics and Policy, Public Economics,
The Subaru FMOS Galaxy Redshift Survey (FastSound). II. The Emission Line Catalog and Properties of Emission Line Galaxies
We present basic properties of 3,300 emission line galaxies detected by
the FastSound survey, which are mostly H emitters at 1.2-1.5
in the total area of about 20 deg, with the H flux sensitivity
limit of at 4.5 sigma. This
paper presents the catalogs of the FastSound emission lines and galaxies, which
will be open to the public in the near future. We also present basic properties
of typical FastSound H emitters, which have H luminosities of
- erg/s, SFRs of 20--500 /yr, and stellar masses
of -- . The 3D distribution maps for the four
fields of CFHTLS W1--4 are presented, clearly showing large scale clustering of
galaxies at the scale of 100--600 comoving Mpc. Based on 1,105 galaxies
with detections of multiple emission lines, we estimate that contamination of
non-H lines is about 4% in the single-line emission galaxies, which are
mostly [OIII]5007. This contamination fraction is also confirmed by
the stacked spectrum of all the FastSound spectra, in which H,
[NII]6548,6583, [SII]6717, 6731, and
[OI]6300,6364 are seen.Comment: 17 pages, 15 figures, accepted for publication in PAS
Numerical simulations of expanding supershells in dwarf irregular galaxies. I. Application to Holmberg I
Numerical hydrodynamical modelling of supernova-driven shell formation is
performed with a purpose to reproduce a giant HI ring (diameter 1.7 kpc) in the
dwarf irregular galaxy Holmberg I (Ho I). We find that the contrast in HI
surface density between the central HI depression and the ring is sensitive to
the shape of the gravitational potential. This circumstance can be used to
constrain the total mass (including the dark matter halo) of nearly face-on
dwarf irregulars. We consider two models of Ho I, which differ by an assumed
mass of the dark matter halo M_h. The contrast in HI surface density between
the central HI depression and the ring, as well as the lack of gas expansion in
the central hole, are better reproduced by the model with a massive halo of
M_h=6.0*10^9 M_sun than by that with a small halo of M_h=4.0*10^8 M_sun,
implying that Ho I is halo-dominated. Assuming the halo mass of 6.0*10^9 M_sum,
we determine the mechanical energy required to form the observed ring equal to
(3.0 +- 0.5)*10^53 ergs, equivalent 300+-50 Type II supernovae. The inclination
of Ho I is constrained to 15-20 degrees by comparing the modelled HI spectrum
and channel maps with those observed.Comment: 11 pages, 11 figures, accepted for publication in Astronomy and
Astrophysic
Very compact millimeter sizes for composite star-forming/AGN submillimeter galaxies
We report the study of far-IR sizes of submillimeter galaxies (SMGs) in
relation to their dust-obscured star formation rate (SFR) and active galactic
nuclei (AGN) presence, determined using mid-IR photometry. We determined the
millimeter-wave (m) sizes of 69 ALMA-identified
SMGs, selected with confidence on ALMA images (--7.4 mJy). We found that all the SMGs are located above an
avoidance region in the millimeter size-flux plane, as expected by the
Eddington limit for star formation. In order to understand what drives the
different millimeter-wave sizes in SMGs, we investigated the relation between
millimeter-wave size and AGN fraction for 25 of our SMGs at --3. We found
that the SMGs for which the mid-IR emission is dominated by star formation or
AGN have extended millimeter-sizes, with respective median and 1.5 kpc. Instead, the SMGs for which
the mid-IR emission corresponds to star-forming/AGN composites have more
compact millimeter-wave sizes, with median
kpc. The relation between millimeter-wave size and AGN fraction suggests that
this size may be related to the evolutionary stage of the SMG. The very compact
sizes for composite star-forming/AGN systems could be explained by supermassive
black holes growing rapidly during the SMG coalescing, star-formation phase.Comment: 9 pages, 4 figures, 1 table. Accepted for publication in ApJ Lette
SXDF-UDS-CANDELS-ALMA 1.5 arcmin deep survey
We have conducted 1.1 mm ALMA observations of a contiguous or 1.5 arcmin window in the SXDF-UDS-CANDELS. We achieved a 5
sensitivity of 0.28 mJy, providing a flat sensus of dusty star-forming galaxies
with (for =40K) up to
thanks to the negative K-correction at this wavelength. We detected 5
brightest sources (S/N6) and 18 low-significance sources (5S/N4; these
may contain spurious detections, though). One of the 5 brightest ALMA sources
( mJy) is extremely faint in the WFC3 and
VLT/HAWK-I images, demonstrating that a contiguous ALMA imaging survey is able
to uncover a faint dust-obscured population that is invisible in deep
optical/near-infrared surveys. We found a possible [CII]-line emitter at
or a low- CO emitting galaxy within the field, which may allow us
to constrain the [CII] and/or the CO luminosity functions across the history of
the universe.Comment: 4 pages, 2 figures, 1 table, to appear in the proceedings of IAU
Symposium 319 "Galaxies at High Redshift and Their Evolution over Cosmic
Time", eds. S. Kaviraj & H. Ferguso
SXDF-ALMA 2 Arcmin^2 Deep Survey: Resolving and Characterizing the Infrared Extragalactic Background Light Down to 0.5 mJy
We present a multi-wavelength analysis of five submillimeter sources (S_1.1mm
= 0.54-2.02 mJy) that were detected during our 1.1-mm-deep continuum survey in
the SXDF-UDS-CANDELS field (2 arcmin^2, 1sigma = 0.055 mJy beam^-1) using the
Atacama Large Millimeter/submillimeter Array (ALMA). The two brightest sources
correspond to a known single-dish (AzTEC) selected bright submillimeter galaxy
(SMG), whereas the remaining three are faint SMGs newly uncovered by ALMA. If
we exclude the two brightest sources, the contribution of the ALMA-detected
faint SMGs to the infrared extragalactic background light is estimated to be ~
4.1^{+5.4}_{-3.0} Jy deg^{-2}, which corresponds to ~ 16^{+22}_{-12}% of the
infrared extragalactic background light. This suggests that their contribution
to the infrared extragalactic background light is as large as that of bright
SMGs. We identified multi-wavelength counterparts of the five ALMA sources. One
of the sources (SXDF-ALMA3) is extremely faint in the optical to near-infrared
region despite its infrared luminosity (L_IR ~ 1e12 L_sun or SFR ~ 100 M_sun
yr^{-1}). By fitting the spectral energy distributions (SEDs) at the
optical-to-near-infrared wavelengths of the remaining four ALMA sources, we
obtained the photometric redshifts (z_photo) and stellar masses (M_*): z_photo
~ 1.3-2.5, M_* ~ (3.5-9.5)e10 M_sun. We also derived their star formation rates
(SFRs) and specific SFRs (sSFRs) as ~ 30-200 M_sun yr^{-1} and ~ 0.8-2
Gyr^{-1}, respectively. These values imply that they are main-sequence
star-forming galaxies.Comment: PASJ accepted, 15 pages, 6 figures, 2 table
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