158 research outputs found
50 Ways To Save Your Heart
If you want to place a winning bet, bet that heart disease will kill you. Yes, you. Why? Because heart disease kills more people in the U.S. than any other disease, including cancer. We want to reverse that bet and save your life. How? You need to read this book and follow its simple recommendations. Many people have already jumped on the bandwagon and defied the probability of dying from heart disease. This book gives you the easy tools to do just that. Prevention costs practically nothing and you donât have to give up anything. You only have to eat and be smart about saving your heart.https://digitalrepository.unm.edu/hsc_facbookdisplay/1000/thumbnail.jp
THE CANADA-FRANCE REDSHIFT SURVEY IX: HST Imaging of High-Redshift Field Galaxies
HST B and I images are presented of 32 CFRS galaxies with secure redshifts in
the range 0.5 < z < 1.2. These galaxies exhibit the same range of morphological
types as seen locally, i.e., ellipticals, spirals and irregulars. The galaxies
look far less regular in the images (rest-frame ultraviolet) than at longer
wavelengths, underlining the fact that optical images of galaxies at still
higher redshift should be interpreted with caution. Quantitative analyses of
the galaxies yield disk sizes, bulge fractions, and colors for each component.
At these redshifts, galaxy disks show clear evidence for surface brightness
evolution. The mean rest-frame central surface brightness of the disks of
normal late-type galaxies is mu_{AB}(B)=20.2 \pm 0.25 mag arcsec^{-2}, about
1.2 mag brighter than the Freeman (1970) value. Some degree of peculiarity is
measurable in 10 (30%) of the galaxies and 4 (13%) show clear signs of
interaction/mergers. There are 9 galaxies (30%) dominated by blue compact
components. These components, which appear to be related to star formation,
occur most often in peculiar/asymmetric galaxies (some of which appear to be
interacting), but a few are in otherwise normal galaxies. Thus, of the galaxies
bluer than present-day Sb, one-third are "blue nucleated galaxies", and half
are late-type galaxies with disks which are significantly brighter than normal
galaxies at z=0. Taken together, these two effects must be responsible for much
of the observed evolution of the luminosity function of blue galaxies.Comment: uuencoded compressed postscript, 8 pages, 1 table + 5 figures in a
separate part. Also available at http://www.astro.utoronto.ca/~lilly/CFRS/ .
Accepted for publication in ApJ Letter
Evolution of Cluster Ellipticals at 0.2 < z < 1.2 from Hubble Space Telescope Imaging
Two-dimensional surface photometry derived from Hubble Space Telescope
imaging is presented for a sample of 225 early-type galaxies (assumed to be
cluster members) in the fields of 9 clusters at redshifts .
The 94 luminous ellipticals (; selected by morphology alone with
no reference to color) form tight sequences in the size-luminosity plane. The
position of these sequences shifts, on average, with redshift so that an object
of a given size at z=0.55 is brighter by mag than
its counterpart (measured with the same techniques) in nearby clusters. At
z=0.9 the shift is mag. If the relation between
size and luminosity is universal so that the local cluster galaxies represent
the evolutionary endpoints of those at high redshift, and if the
size-luminosity relation is not modified by dynamical processes then this
population of galaxies has undergone significant luminosity evolution since z=1
consistent with expectations based on models of passively evolving, old stellar
populations.Comment: 7 pages, 3 figures, and 1 Tabl
The Gravitational Lens CFRS03.1077
An exquisite gravitational arc with a radius of 2.1" has been discovered
around the z = 0.938 field elliptical galaxy CFRS03.1077 during HST
observations of Canada-France Redshift Survey (CFRS) fields. Spectroscopic
observations of the arc show that the redshift of the resolved lensed galaxy is
z = 2.941. This gravitational lens-source system is well-fitted using the
position angle and ellipticity derived from the visible matter distribution and
an isothermal mass profile with a mass corresponding to sigma =387+-5 km/s.
Surprisingly, given the evidence for passive evolution of elliptical galaxies,
this is in good agreement with an estimate based on the fundamental plane for z
= 0 ellipticals. This, perhaps, indicates that this galaxy has not shared in
the significant evolution observed for average elliptical galaxies at z ~ 1. A
second elliptical galaxy with similar luminosity from the CFRS survey, CFRS
14.1311 at z=0.807, is also a lens but in this case the lens model gives a much
smaller mass-to-light ratio, i.e., it appears to confirm the expected
evolution. This suggests that this pair of field elliptical galaxies may have
very different evolutionary histories, a significant result if confirmed.
Clearly, CFRS03.1077 demonstrates that these "Einstein rings" are powerful
probes of high redshift galaxies.Comment: 11 pages, 5 figures, accepted by Ap.
Discovery of a New Quadruple Lens HST 1411+5211
Gravitational lensing is an important tool for probing the mass distribution
of galaxies. In this letter we report the discovery of a new quadruple lens HST
1411+5211 found in archived WFPC2 images of the galaxy cluster CL140933+5226.
If the galaxy is a cluster member then its redshift is . The images of
the source appear unresolved in the WFC implying that the source is a quasar.
We have modeled the lens as both a single galaxy and a galaxy plus a cluster.
The latter model yields excellent fits to the image positions along with
reasonable parameters for the galaxy and cluster making HST 1411+5211 a likely
gravitational lens. Determination of the source redshift and confirmation of
the lens redshift would allow us to put strong constraints on the mass
distribution of the lensing galaxy.Comment: 11 pages including 1 postscript figure, aastex. Accepted to the ApJL.
Also available from:
http://www.astro.lsa.umich.edu:80/users/philf/www/papers/list.htm
Hubble Space Telescope Imaging of the CFRS and LDSS Redshift Surveys---III. Field elliptical galaxies at 0.2 < z < 1.0
Surface photometry has been performed on a sample of 46 field elliptical
galaxies. These galaxies are described well by a deVaucouleurs R^{1/4} profile.
The sample was selected from the combined Canada-France and LDSS redshift
surveys and spans the range 0.20 < z < 1.00. The relationship between galaxy
half-light radius and luminosity evolves such that a galaxy of a given size is
more luminous by Delta M_B=-0.97 \pm 0.14 mag at z=0.92 and the mean rest-frame
color shifts blueward by Delta (U-V) =-0.68 \pm 0.11 at z=0.92 relative to the
local cluster relations. Approximately 1/3 of these elliptical galaxies exhibit
[OII] 3727 emission lines with equivalent widths > 15 angstroms indicating
ongoing star formation. Estimated star-formation rates imply that \le 5% of the
stellar mass in the elliptical galaxy population has been formed since z=1. We
see no evidence for a decline in the space density of early-type galaxies with
look-back time. The statistics and a comparison with local
luminosity functions are both consistent with the view that the population of
massive early-type galaxies was largely in place by z~1. This implies that
merging is not required since that time to produce the present-day space
density of elliptical galaxies.Comment: 21 pages plus 8 figures plus 5 tables. Accepted by Astrophysical
Journa
Observatory/data centre partnerships and the VO-centric archive: The JCMT Science Archive experience
We present, as a case study, a description of the partnership between an
observatory (JCMT) and a data centre (CADC) that led to the development of the
JCMT Science Archive (JSA). The JSA is a successful example of a service
designed to use Virtual Observatory (VO) technologies from the start. We
describe the motivation, process and lessons learned from this approach.Comment: Accepted for publication in the second Astronomy & Computing Special
Issue on the Virtual Observatory; 10 pages, 5 figure
Shape of the Galactic Orbits in the CNOC1 Clusters
We present an analysis of the orbital properties in 9 intermediate-redshifts
cluster of the CNOC1 survey and we compare them to a control sample of 12
nearby clusters. Similar to the nearby elliptical galaxies, the bulge-dominated
galaxies in clusters at redshifts ~0.1-0.4 present orbits that are more
eccentric than those for disk-dominated galaxies. However, the orbital
segregation is less significant than that found for elliptical and spiral
galaxies in nearby cluster. When galaxies are separated by colors - red
galaxies with colors in the rest frame (U-V)_o > 1.4, and blue galaxies with
(U-V)_o =< 1.4 - the strongest orbital segregation is found. Therefore, the
segregation we found seems to modify more efficiently the star formation
activity than the internal shape of the galaxies. When we compare the orbits of
early-type galaxies at intermediate-redshift with those for z=0, they seem to
develop significant changes getting much more eccentric. A different behavior
is observed in the late-type galaxies, which present no-significant evolution
in their orbit shapes.Comment: Accepted for publication in ApJ, April 2000. Latex with aaspp4.sty,
20 pages, 4 tables, 6 eps figure
The Size Function of Galaxy Disks out to z ~ 1 from the Canada-France-Hawaii-Telescope Legacy Survey
The formation and growth of galaxy disks over cosmic time is crucial to our
understanding of galaxy formation. Despite steady improvements in the size and
quality of disk samples over the last decade, many aspects of galaxy disk
evolution remain unclear. Using two square degrees of deep, wide-field i'-band
imaging from the Canada-France-Hawaii Telescope Legacy Survey, we compute size
functions for 6000 disks from z=0.2 to z=1 and explore luminosity and number
density evolution scenarios with an emphasis on the importance of selection
effects on the interpretation of the data. We also compute the size function of
a very large sample of disks from the Sloan Digital Sky Survey to use as a
local (z ~ 0.1) comparison. CFHTLS size functions computed with the same fixed
luminosity-size selection window at all redshifts exhibit evolution that
appears to be best modelled by a pure number density evolution. The z = 0.3
size function is an excellent match to the z = 0.9 one if disks at the highest
redshift are a factor of 2.5 more abundant than in the local universe. The SDSS
size function would also match the z = 0.9 CFHTLS size function very well with
a similar change in number density. On the other hand, the CFHTLS size
functions computed with a varying luminosity-size selection window with
redshift remain constant if the selection window is shifted by 1.01.5 mag
towards fainter magnitudes with decreasing redshift. There is a weak dependence
on disk scale length with smaller ( 4 kpc) disks requiring more
luminosity evolution than larger ones. Given that changes in number density are
primarily due to mergers and that current estimates of merger rates below z = 1
are low, luminosity evolution appears to be a more plausible scenario to
explain the observations.Comment: 11 pages, 9 figures, Accepted for publication in Ap
- âŠ