3,334 research outputs found
Large-Scale Structures Behind the Southern Milky Way from Observations of Partially Obscured Galaxies
We report here on extragalactic large-scale structures uncovered by a deep
optical survey for galaxies behind the southern Milky Way. Systematic visual
inspection of the ESO/SRC-survey revealed over 10000 previously unknown
galaxies in the region 265 < l < 340, |b| < 10. With subsequently obtained
redshifts of more than 10% of these galaxies, new structures across the Milky
Way are unveiled, such as a filament at ~ 2500 km/s connecting to the Hydra
and Antlia clusters, a shallow extended supercluster in Vela (~ 6000km/s), and
a nearby (4882 km/s), very massive (M ~ 2-5 10^15 Msun), rich Coma-like cluster
which seems to constitute the previously unidentified center of the Great
Attractor. The innermost part of the Milky Way where the foreground obscuration
in the blue is 5mag, respectively HI-column densities greater than 6 10^21 /
cm^2 remains fully opaque. In this approximately 8 degrees wide strip, the
forthcoming blind HI-survey with the multi-beam system at Parkes will provide
the only tool to unveil this part of the extragalactic sky.Comment: Presented at the Multibeam Workshop on ``HI in the Local Universe'',
Sydney, May 13-15 1996. Accepted 2.11.1996 for publication by PASA.
Latex-file with 4 encapsulated postscript files. Version with original
figures available at
http://www.atnf.csiro.au/~lstavele/13beam/proceedings/korteweg/korteweg.htm
DENIS Observations of Multibeam Galaxies in the Zone of Avoidance
Roughly 25% of the optical extragalactic sky is obscured by the dust and
stars of our Milky Way. Dynamically important structures might still lie hidden
in this zone. Various surveys are presently being employed to uncover the
galaxy distribution in the Zone of Avoidance (ZOA) but all suffer from
(different) limitations and selection effects.
We illustrate the promise of using a multi-wavelength approach for
extragalactic large-scale studies behind the ZOA, i.e. a combination of three
surveys -- optical, systematic blind HI and near-infrared (NIR), which will
allow the mapping of the peculiar velocity field in the ZOA through the NIR
Tully-Fisher relation. In particular, we present here the results of
cross-identifying HI-detected galaxies with the DENIS NIR survey, and the use
of NIR colours to determine foreground extinctions.Comment: Accepted for publication in PASA. Proceedings of workshop "HI in the
Local Universe, II", held in Melbourne, Sept. 1998. 9 pages, LaTeX2e, 2
encapsulated PS figures, 3 JPEG figures, Full resolution figures 2, 3 and 4
and full resolution paper are at
ftp://ftp.iap.fr/pub/from_users/gam/PAPERS/HICONF
Quarkonium Production Studies in CMS
When the LHC starts its operation, CMS will have a unique opportunity to
study q uarkonium production in pp collisions and later in PbPb collisions.
Here we report on the methods and plans for measuring the differential pT
Jpsi->mu+mu- production cross section, using data to be collected in the first
LHC run by the CMS detector. Furthermore we discuss the performance of the CMS
detector for quarkonium measurements in PbPb collisions.Comment: Presented at the 34th International Conference on High Energy Physic
An Overview of Uncovered and Suspected Large-Scale Structures behind the Milky Way
Various dynamically important extragalactic large-scale structures in the
local Universe lie behind the Milky Way. Most of these structures (predicted
and unexpected) have only recently been made ``visible'' through dedicated deep
surveys at various wavelengths. The wide range of observational searches
(optical, near infrared, far infrared, radio and X-ray) for galaxies in the
Zone of Avoidance (ZOA) will be reviewed and the uncovered and suspected
large-scale structures summarised. Particular emphasis is given to the Great
Attractor region where the existence of yet another cluster is suspected (Woudt
1998). Predictions from reconstructions of the density field in the ZOA are
discussed and compared with observational evidence. Although no major
structures are predicted out to about v < 10000 km/s for which no observational
evidence exists, the comparison between reconstructed density fields and the
observed galaxy distribution remain important as they allow derivations of the
density and biasing parameters.Comment: To appear in PASA 16. Proceedings of workshop "HI in the Local
Universe, II", held in Melbourne, Sept. 1998. 9 pages, LaTeX2e, 1
encapsulated PS figur
Extragalactic Large-Scale Structures behind the Southern Milky Way. IV. Redshifts Obtained with MEFOS
Abbreviated: As part of our efforts to unveil extragalactic large-scale
structures behind the southern Milky Way, we here present redshifts for 764
galaxies in the Hydra/Antlia, Crux and Great Attractor region (266deg < l <
338deg, |b| < 10deg), obtained with the Meudon-ESO Fibre Object Spectrograph
(MEFOS) at the 3.6-m telescope of ESO. The observations are part of a redshift
survey of partially obscured galaxies recorded in the course of a deep optical
galaxy search behind the southern Milky Way. A total of 947 galaxies have been
observed, a small percentage of the spectra (N=109, 11.5%) were contaminated by
foreground stars, and 74 galaxies (7.8%) were too faint to allow a reliable
redshift determination. With MEFOS we obtained spectra down to the faintest
galaxies of our optical galaxy survey, and hence probe large-scale structures
out to larger distances (v <~ 30000 km/s) than our other redshift follow-ups.
The most distinct large-scale structures revealed in the southern Zone of
Avoidance are discussed in context to known structures adjacent to the Milky
Way.Comment: 11 pages, 7 figures; accepted for publication in A&A. Tables 1 and 2
will be available in electronic format at the CDS. Figure 1 at full
resolution, and both tables are available at
http://mensa.ast.uct.ac.za/~pwoudt/data/H4462/
Large-Scale Structures Behind the Milky Way from Near-IR Surveys
About 25% of the optical extragalactic sky is obscured by the dust and stars
of our Milky Way. Dynamically important structures might still lie hidden in
this zone. Various approaches are presently being employed to uncover the
galaxy distribution in the Zone of Avoidance (ZOA) but all suffer from
(different) limitations and selection effects.
We investigated the potential of using the DENIS NIR survey for studies of
galaxies behind the obscuration layer of our Milky Way and for mapping the
Galactic extinction. As a pilot study, we recovered DENIS I, J and K band
images of heavily obscured but optically still visible galaxies. We determined
the I, J and K band luminosity functions of galaxies on three DENIS strips that
cross the center of the nearby, low-latitude, rich cluster Abell 3627. The
extinction-corrected I-J and J-K colours of these cluster galaxies compare well
with that of an unobscured cluster. We searched for and identified galaxies at
latitudes where the Milky Way remains fully opaque (|b|
4-5mag) - in a systematic search as well as around positions of galaxies
detected with the blind HI survey of the ZOA currently conducted with the
Multibeam Receiver of the Parkes Radiotelescope.Comment: 12 pages, including 5 PS figures, LaTeX, uses crckapb.sty and
epsf.tex. Better resolved figures available upon request. To appear in
proceedings of the 3rd Euroconference (Meudon, France, June 1997) on ``The
Impact of Near IR Surveys'', Kluwer 199
- …