5,970 research outputs found
Tracing Recent Star Formation of Red Early-type Galaxies out to 1
We study the mid-infrared (IR) excess emission of early-type galaxies (ETGs)
on the red-sequence at 1 using a spectroscopic sample of galaxies in the
fields of Great Observatories Origins Deep Survey (GOODS). In the mass-limited
sample of 1025 galaxies with 10 and
, we identify 696 24 m detected (above the
5) galaxies and find them to have a wide range of NUV- and -[12
m] colors despite their red optical colors. Even in the sample of
very massive ETGs on the red sequence with 10
, more than 18% show excess emission over the photospheric emission
in the mid-IR. The combination with the results of red ETGs in the local
universe suggests that the recent star formation is not rare among quiescent,
red ETGs at least out to if the mid-IR excess emission results from
intermediate-age stars or/and from low-level ongoing star formation. Our
colorcolor diagram including near-UV and mid-IR emissions are efficient not
only for identifying ETGs with recent star formation, but also for
distinguishing quiescent galaxies from dusty star-forming galaxies.Comment: 25 pages, 9 figures, accepted for publication in Ap
To the Edge of M87 and Beyond: Spectroscopy of Intracluster Globular Clusters and Ultra Compact Dwarfs in the Virgo Cluster
We present the results from a wide-field spectroscopic survey of globular
clusters (GCs) in the Virgo Cluster. We obtain spectra for 201 GCs and 55
ultracompact dwarfs (UCDs) using the Hectospec on the Multiple Mirror
Telescope, and derive their radial velocities. We identify 46 genuine
intracluster GCs (IGCs), not associated with any Virgo galaxies, using the 3D
GMM test on the spatial and radial velocity distribution.They are located at
the projected distance 200 kpc R 500 kpc from the center
of M87. The radial velocity distribution of these IGCs shows two peaks, one at
= 1023 km s associated with the Virgo main body, and another
at = 36 km s associated with the infalling structure. The
velocity dispersion of the IGCs in the Virgo main body is 314 km s, which is smoothly connected to the velocity dispersion
profile of M87 GCs, but much lower than that of dwarf galaxies in the same
survey field, 608 km s. The UCDs are more
centrally concentrated on massive galaxies, M87, M86, and M84. The radial
velocity dispersion of the UCD system is much smaller than that of dwarf
galaxies. Our results confirm the large-scale distribution of Virgo IGCs
indicated by previous photometric surveys. The color distribution of the
confirmed IGCs shows a bimodality similar to that of M87 GCs. This indicates
that most IGCs are stripped off from dwarf galaxies and some from massive
galaxies in the Virgo.Comment: 19 pages, 20 figures, 8 tables, accepted for publication in Ap
SUSTAINABLE DEVELOPMENT OF OFFSHORE SOFTWARE OUTSOURCING IN VIETNAM: THE CASE OF FPT SOFTWARE
The aims of the paper are to describe the Vietnamese offshore software outsourcing industry and to investigate key success factors of the largest offshore software outsourcing company in Vietnam, FPT Software. Vietnam has taken ICT industry a strategic one for its economic development, and it has been showing high growth in that field. Especially, Vietnam has potential to be successful in offshore software outsourcing, but Vietnam won\u27t be sustainable in this competitive market unless it overcomes several weaknesses. FPT Software as the best achiever so far is a good model for Vietnamese software companies. The key success factors of sustainable development in FPT Software are found in good managerial practices, application of international quality standards for software development, and highly motivated and skilled workforces. Based on the case study, we discuss the sustainability of Vietnam\u27s offshore software outsourcing
Measuring at future B-Factories
We calculate the so--called Fermi motion parameter of ACCMM model
using the variational method in a potential model approach. We also propose
hadronic invariant mass distribution as an alternative experimental observable
to measure at future asymmetric factories.Comment: 9 pages (1 fugure not included
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