862 research outputs found
The Chemical Properties of Milky Way and M31 Globular Clusters: I. A Comparative Study
A comparative analysis is performed between high-quality integrated spectra
of 30 globular clusters in M31, 20 Milky Way clusters, and a sample of field
and cluster elliptical galaxies. We find that the Lick CN indices in the M31
and Galactic clusters are enhanced relative to the bulges of the Milky Way,
M31, and elliptical spheroids. Although not seen in the Lick CN indices, the
near-UV cyanogen feature (3883 A) is strongly enhanced in M31 clustesr with
respect to the Galactic globulars at metallicities, --1.5<[Fe/H]<--0.3. Carbon
shows signs of varying amongst these two groups. For [Fe/H]>--0.8, we observe
no siginificant differences in the Hdelta, Hgamma, or Hbeta indices between the
M31 and Galactic globulars. The sample of ellipticals lies offset from the loci
of all the globulars in the Cyanogen--[MgFe], and Balmer--[MgFe] planes. Six of
the M31 cluster spectra appear young, and are projected onto the M31 disk.
Population synthesis models suggest that these are metal-rich clusters with
ages 100--800 Myr, metallicities --0.20 < [Fe/H] <0.35, and masses 0.7
-7.0x10^4 Msun. Two other young clusters are Hubble V in NGC 205, and an older
(~3 Gyr) cluster ~7 kpc away from the plane of the disk. The six clusters
projected onto the disk rotate in a similar fashion to the HI gas in M31, and
three clusters exhibit thin disk kinematics (Morrison et al.). Dynamical masses
and structural parameters are required for these objects to determine whether
they are massive open clusters or globular clusters. If the latter, our
findings suggest globular clusters may trace the build up of galaxy disks. In
either case, we conclude that these clusters are part of a young, metal-rich
disk cluster system in M31, possibly as young as 1 Gyr old.Comment: 52 pages, 14 figures, 8 tables, minor revisions in response to
referee, conclusions remain the same. Scheduled to appear in the October 2004
issue of The Astronomical Journa
Globular clusters in the outer halo of M31: the survey
We report the discovery of 40 new globular clusters (GCs) that have been
found in surveys of the halo of M31 based on INT/WFC and CHFT/Megacam imagery.
A subset of these these new GCs are of an extended, diffuse nature, and include
those already found in Huxor et al. (2005). The search strategy is described
and basic positional and V and I photometric data are presented for each
cluster. For a subset of these clusters, K-band photometry is also given. The
new clusters continue to be found to the limit of the survey area (~100 kpc),
revealing that the GC system of M31 is much more extended than previously
realised. The new clusters increase the total number of confirmed GCs in M31 by
approximately 10% and the number of confirmed GCs beyond 1 degree (~14 kpc) by
more than 75%. We have also used the survey imagery as well recent HST archival
data to update the Revised Bologna Catalogue (RBC) of M31 globular clusters.Comment: Accepted to MNRA
The M31 Globular Cluster Luminosity Function
We combine our compilation of photometry of M31 globular cluster and probable
cluster candidates with new near-infrared photometry for 30 objects. Using
these data we determine the globular cluster luminosity function (GCLF) in
multiple filters for the M31 halo clusters. We find a GCLF peak and dispersion
of V_0^0=16.84 +/-0.11, sigma_t=0.93 +/- 0.13 (Gaussian sigma = 1.20 +/- 0.14),
consistent with previous results. The halo GCLF peak colors (e.g., B^0_0 -
V^0_0) are consistent with the average cluster colors. We also measure V-band
GCLF parameters for several other subsamples of the M31 globular cluster
population. The inner third of the clusters have a GCLF peak significantly
brigher than that of the outer clusters (delta V =~ 0.5mag). Dividing the
sample by both galacticentric distance and metallicity, we find that the GCLF
also varies with metallicity, as the metal-poor clusters are on average 0.36
mag fainter than the metal-rich clusters. Our modeling of the catalog selection
effects suggests that they are not the cause of the measured differences, but a
more complete, less-contaminated M31 cluster catalog is required for
confirmation. Our results imply that dynamical destruction is not the only
factor causing variation in the M31 GCLF: metallicity, age, and cluster initial
mass function may also be important.Comment: AJ, in press. 36 pages, including 7 figure
Mariticide in Milan between 1990 and 2017 : a criminological and medico-legal analysis
Most murder victims in a romantic relationship are women but sometimes they will kill their husbands or partners (mariticide). This paper focuses on these rarer cases using a sample taken from the autopsy reports of the Department of Legal Medicine of the University of Milan whose territory includes the municipality of Milan and part of the province of Milan and Monza \u2013 approximately four million inhabitants
Gestational weight gain in overweight and obese women enrolled in a healthy lifestyle and eating habits program
OBJECTIVES:
To determine whether changes in lifestyle in women with BMI > 25 could decrease gestational weight gain and unfavorable pregnancy outcomes.
METHODS:
Women with BMI > 25 were randomized at 1st trimester to no intervention or a Therapeutic Lifestyle Changes (TLC) Program including diet (overweight: 1700 kcal/day, obese: 1800 kcal/day) and mild physical activity (30 min/day, 3 times/week). At baseline and at the 36th week women filled-in a Food Frequency Questionnaire.
OUTCOMES:
gestational weight gain, gestational diabetes mellitus, gestational hypertension, preterm delivery. Data stratified by BMI categories.
RESULTS:
Socio-demographic features were similar between groups (TLC: 33 cases,
CONTROLS:
28 cases). At term, gestational weight gain in obese women randomized to TLC group was lower (6.7 ± 4.3 kg) versus controls (10.1 ± 5.6 kg, p = 0.047). Gestational diabetes mellitus, gestational hypertension and preterm delivery were also significantly lower. TLC was an independent factor in preventing gestational weight gain, gestational diabetes mellitus, gestational hypertension. Significant changes in eating habits occurred in the TLC group, which increased the number of snacks, the intake of fruits-vegetables and decreased the consumption of sugar.
CONCLUSIONS:
A caloric restriction associated to changes in eating behavior and constant physical activity, is able to reduce gestational weight gain and related pregnancy complications in obese women.Objectives: To determine whether changes in lifestyle in women with BMI > 25 could decrease gestational weight gain and unfavorable pregnancy outcomes. Methods: Women with BMI > 25 were randomized at 1st trimester to no intervention or a Therapeutic Lifestyle Changes (TLC) Program including diet (overweight: 1700 kcal/day, obese: 1800 kcal/day) and mild physical activity (30 min/day, 3 times/week). At baseline and at the 36th week women filled-in a Food Frequency Questionnaire. Outcomes: gestational weight gain, gestational diabetes mellitus, gestational hypertension, preterm delivery. Data stratified by BMI categories. Results: Socio-demographic features were similar between groups (TLC: 33 cases, Controls: 28 cases). At term, gestational weight gain in obese women randomized to TLC group was lower (6.7 ± 4.3 kg) versus controls (10.1 ± 5.6 kg, p = 0.047). Gestational diabetes mellitus, gestational hypertension and preterm delivery were also significantly lower. TLC was an independent factor in preventing gestational weight gain, gestational diabetes mellitus, gestational hypertension. Significant changes in eating habits occurred in the TLC group, which increased the number of snacks, the intake of fruits-vegetables and decreased the consumption of sugar. Conclusions: A caloric restriction associated to changes in eating behavior and constant physical activity, is able to reduce gestational weight gain and related pregnancy complications in obese women. © 2014 Informa UK Ltd
The discovery of 2.78 hour periodic modulation of the X-ray flux from globular cluster source Bo 158 in M31
We report the discovery of periodic intensity dips in the X-ray source XMMU
J004314.1+410724, in the globular cluster Bo158 in M31. The X-ray flux was
modulated by ~83% at a period of 2.78 hr (10017 s) in an XMM-Newton observation
taken 2002 Jan 6-7. The X-ray intensity dips show no energy dependence. We
detected weaker dips with the same period in observations taken 2000 June 25
(XMM-Newton) and 1991 June 26 (ROSAT/PSPC). The amplitude of the modulation has
been found to be anticorrelated with source X-ray flux: it becomes lower when
the source intensity rises. The energy spectrum of Bo158 was stable from
observation to observation, with a characteristic cutoff at ~4-6 keV. The
photo-electric absorption was consistent with the Galactic foreground value. No
significant spectral changes were seen in the course of the dips. If the 2.78
hr cycle is the binary period of Bo158 the system is highly compact, with a
binary separation of ~10e11 cm. The association of the source with a globular
cluster, together with spectral parameters consistent with Galactic neutron
star sources, suggests that X-rays are emitted by an accreting neutron star.
The properties of Bo 158 are somewhat reminiscent of the Galactic X-ray sources
exhibiting a dip-like modulations. We discuss two possible mechanisms
explaining the energy-independent modulation observed in Bo 158: i) the
obscuration of the central source by highly ionized material that scatters
X-rays out of the line of sight; ii) partial covering of an extended source by
an opaque absorber which occults varying fractions of the source.Comment: 10 pages, 4 figures, ApJ, submitted, uses emulateapj styl
A First Look at the Nuclear Region of M31 with Chandra
We report on the first observation of the nuclear region of M31 with the
Chandra X-ray Observatory. The nuclear source seen with the Einstein and ROSAT
HRIs is resolved into five point sources. One of these sources is within 1'' of
the M31 central super-massive black hole. As compared to the other point
sources in M31, this nuclear source has an unusual x-ray spectrum. Based on the
spatial coincidence we identify this source with the central black hole, and
note that the unusual spectrum is a challenge to current theories. A bright
transient is detected ~26'' to the west of the nucleus, which may be associated
with a stellar mass black hole.Comment: Submitted to ApJ Letters, 4 pages, 4 figures. email:
garcia,ssm,fap,wrf,jem,cjf, @head-cfa.harvard.ed
Effects of cooking and storage methods on the micronutrient content of foods.
Food processing has the potential to alter the nutrient quality of foods. This review deals with the effects of home-based cooking and storage practices on the micronutrient content of foods. It describes the effects of cooking, freezing and refrigeration on the vitamin and mineral content of meats, fish, fruit, vegetables and cereals. Based on this review, we suggest that the consumer should be aware of the possibility that losses in nutritional quality of foods may result from an improper use of cooking and storage techniques available at home
On the X-ray source luminosity distributions in the bulge and disk of M31: First results from XMM-Newton survey
We present luminosity distributions for the X-ray sources detected with
XMM-Newton in the bulge and disk of the Andromeda Galaxy (M31). The disk is
clearly lacking the brighter sources which dominate X-ray emission from the
bulge. This is the first convincing evidence for a difference between bulge and
disk X-ray populations in M31. Our results are in good qualitative agreement
with the luminosity distributions for low- and high-mass X-ray binaries
recently obtained by Grimm et al.(2001) for our Galaxy. This confirms that
X-ray population of the disk of M31 is dominated by fainter HMXB sources, while
the bulge is populated with brighter LMXBs.Comment: 5 pages, 2 figures, uses emulateapj.sty, Submitted to ApJ
The Disk and Extraplanar Environment of NGC 247
The stellar content of the spiral galaxy NGC 247 is investigated. The main
sequence turn-off (MSTO) in the inner 12 kpc of the disk corresponds to an age
of 6 Myr. A mean star formation rate (SFR) of 0.1 solar masses per year during
the past 16 Myr is computed from star counts. The color of the red supergiant
plume does not change with radius, suggesting that the mean metallicity of
young stars does not vary by more than 0.1 dex. The number of bright main
sequence stars per local stellar mass density climbs towards larger radii out
to a distance of 12 kpc; the scale lengths that characterize the radial
distributions of young and old stars in the disk thus differ. The density of
bright main sequence stars with respect to projected HI mass gradually drops
with increasing radius. The population of very young stars disappears in the
outer disk; the MSTO at galactocentric radii between 12 and 15 kpc corresponds
to 16 Myr, while between 15 and 18 kpc the age is > 40 Myr. Red giant branch
(RGB) stars are resolved at a projected minor axis galactocentric distance of
12 kpc. There is a broad spread in metallicity among the RGB stars, with a mean
[M/H] = -1.2. The RGB-tip occurs at i' = 24.5 +/- 0.1, indicating that the
distance modulus is 27.9 +/- 0.1. Luminous AGB stars with an age 3 Gyr are also
seen in this field.Comment: Includes 16 eps figures; to appear in the Astrophysical Journa
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