Abstract
The Next Generation Virgo Cluster Survey (NGVS) was designed to provide a deep census of baryonic structures in the Virgo cluster. The survey covers the 104 deg
2
area from the core of Virgo ...out to one virial radius, in the
u
*
griz
bandpasses, to a point-source depth of
g
∼ 25.9 mag (10
σ
) and a single pixel surface brightness limit of
μ
g
∼ 29 mag arcsec
−2
(2
σ
above the sky). Here we present the final catalog of 404 Virgo galaxies located within a 3.71 deg
2
(0.3 Mpc
2
) region centered on M87, Virgo’s dominant galaxy. Of these, 154 were previously uncataloged and span the range 17.8 mag <
g
< 23.7 mag (−13.4 mag <
M
g
< −7.4 mag at the 16.5 Mpc distance of Virgo). Extensive simulations show that the NGVS catalog is complete down to
g
= 18.6 mag (
M
g
= −12.5 mag, corresponding to a stellar mass
for an old stellar population), and 50% complete at
g
= 22.0 mag (
M
g
= −9.1 mag,
). The NGVS 50% completeness limit is 3 mag deeper than that of the Virgo Cluster Catalog (VCC), which has served as Virgo’s reference standard for over a quarter century, and 2 mag deeper than the VCC detection limit. We discuss the procedure adopted for the identification of objects and the criteria used to assess cluster membership. For each of the 404 galaxies in the NGVS Virgo Cluster core catalog, we present photometric and structural parameters based on a nonparametric curve-of-growth and isophotal analysis, as well as parametric (Sérsic, double-Sérsic, and/or core-Sérsic) fits to the one-dimensional surface brightness profiles and two-dimensional light distributions.
ABSTRACT We investigate the intrinsic shapes of low-luminosity galaxies in the central 300 kpc of the Virgo Cluster using deep imaging obtained as part of the Next Generation Virgo Cluster Survey ...(NGVS). We build a sample of nearly 300 red-sequence cluster members in the yet-unexplored −14 < Mg < −8 mag range, and we measure their apparent axis ratios, q, through Sérsic fits to their two-dimensional light distribution, which is well described by a constant ellipticity parameter. The resulting distribution of apparent axis ratios is then fit by families of triaxial models with normally distributed intrinsic ellipticities, E = 1 − C/A, and triaxialities, T = (A2 − B2)/(A2 − C2). We develop a Bayesian framework to explore the posterior distribution of the model parameters, which allows us to work directly on discrete data, and to account for individual, surface-brightness-dependent axis ratio uncertainties. For this population we infer a mean intrinsic ellipticity = and a mean triaxiality = . This implies that faint Virgo galaxies are best described as a family of thick, nearly oblate spheroids with mean intrinsic axis ratios 1:0.94:0.57. The core of Virgo lacks highly elongated low-luminosity galaxies, with 95% of the population having q > 0.45. We additionally attempt a study of the intrinsic shapes of Local Group (LG) satellites of similar luminosities. For the LG population we infer a slightly larger mean intrinsic ellipticity = , and the paucity of objects with round apparent shapes translates into more triaxial mean shapes, 1:0.76:0.49. Numerical studies that follow the tidal evolution of satellites within LG-sized halos are in good agreement with the inferred shape distributions, but the mismatch for faint galaxies in Virgo highlights the need for more adequate simulations of this population in the cluster environment. We finally compare the intrinsic shapes of NGVS low-mass galaxies with samples of more massive quiescent systems, and with field, star-forming galaxies of similar luminosities. We find that the intrinsic flattening in this low-luminosity regime is almost independent of the environment in which the galaxy resides, but there is a hint that objects may be slightly rounder in denser environments. The comparable flattening distributions of low-luminosity galaxies that have experienced very different degrees of environmental effects suggest that internal processes are the main drivers of galaxy structure at low masses, with external mechanisms playing a secondary role.
The Next Generation Virgo Cluster Survey (NGVS) was designed to provide a deep census of baryonic structures in the Virgo cluster. The survey covers the 104 deg2 area from the core of Virgo out to ...one virial radius, in the u*griz bandpasses, to a point-source depth of g ∼ 25.9 mag (10 ) and a single pixel surface brightness limit of g ∼ 29 mag arcsec−2 (2 above the sky). Here we present the final catalog of 404 Virgo galaxies located within a 3.71 deg2 (0.3 Mpc2) region centered on M87, Virgo's dominant galaxy. Of these, 154 were previously uncataloged and span the range 17.8 mag < g < 23.7 mag (−13.4 mag < Mg < −7.4 mag at the 16.5 Mpc distance of Virgo). Extensive simulations show that the NGVS catalog is complete down to g = 18.6 mag (Mg = −12.5 mag, corresponding to a stellar mass for an old stellar population), and 50% complete at g = 22.0 mag (Mg = −9.1 mag, ). The NGVS 50% completeness limit is 3 mag deeper than that of the Virgo Cluster Catalog (VCC), which has served as Virgo's reference standard for over a quarter century, and 2 mag deeper than the VCC detection limit. We discuss the procedure adopted for the identification of objects and the criteria used to assess cluster membership. For each of the 404 galaxies in the NGVS Virgo Cluster core catalog, we present photometric and structural parameters based on a nonparametric curve-of-growth and isophotal analysis, as well as parametric (Sérsic, double-Sérsic, and/or core-Sérsic) fits to the one-dimensional surface brightness profiles and two-dimensional light distributions.
Dihydropyran-2-one possessing a sulfamate moiety at the 4-position of the thiophenyl ring were designed to reach S
3′ pocket of the HIV protease. Synthetic routes for the preparation of thiotosylates ...possessing 3-(2-
t-butyl-5-methyl-4-sulfamate) phenylthio moiety were established. SAR of various sulfamate analogs including HIV protease binding affinities, antiviral activities and therapeutic indices will be described.
Graphic
Dihydropyran-2-ones possessing amino and carboxamide functionalities on 3-SPh (2-
tert-butyl, 5-methyl) ring were synthesized and evaluated for their antiviral activities. Both the enantiomers of ...inhibitor
15 were synthesized. The in vitro resistance profile, inhibitory activities against cytochrome P450 isozymes and pharmacokinetic properties of inhibitor
15S
will be discussed.
Few dairymen will deny that the most costly disease which they observe in their cows is mastitis. Bovine mastitis, although by no means a newly recognized disease is surrounded by more confusion on ...the means of control than any other disease. It has always been necessary to determine the cause of a disease before control measures can be developed. Therein lies the problem of bovine mastitis. All the years of research have only confirmed the complexity of the disease and its many etiological agents.
Although it has many etiological causes, it is basically caused by an interplay between mechanical forces (milking machine) and bacterial infection. Nutrition, heredity, and environment may also be involved but not to the extent of the previous two factors.
The role of the milking machine in mastitis is threefold. First, it acts as a vector in transmission of the organism involved. Secondly, it causes trauma which is necessary to incite many forms of the disease. Thirdly, it actively injects bacteria into the gland under certain circumstances.
We recently described the synthesis and characterization of MDL 105,212, a non peptide tachykinin antagonist with high affinity for NK
1 and NK
2 receptors.
1 Here we report the synthesis and ...structure-activity relationships for a series of analogs of MDL 105,212 with regards to: NK
1 and NK
2 receptor binding affinity, physical-chemical characterization; in vitro absorption potential; in vitro metabolic stability; and efficacy in a capsaicin-challenge conscious guinea pig model after oral administration.
We report the synthesis and structure activity relationships for a series of analogs of MDL 105,212 with regards to: NK
1 and NK
2 receptor binding affinity, physical-chemical characterization, in vitro absorption potential, in vitro metabolic stability, and efficacy in a capsaicin-challenge conscious guinea pig model after oral administration.
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