Transcript ESO Greatest Hits The H Index Rank papers by citations. H is the paper for which number of citations equals the rank.

ESO Greatest Hits
The H Index
Rank papers by citations. H is the paper for which number
of citations equals the rank. H increases with time.
Some Statistics
Year
La Silla
VLT
Papers
2001
324 (18)
103 (40)
2002
291 (19)
161 (32)
2003
314 (17)
260 (29)
2004
326 (13)
340 (23)
2005
275 (6)
356 (10)
2006 (*)
246
370 (**)
(*) Until December 12.
(**) Apex: 21; archive: 61
La Silla Statistics
Mean statistics
C ES
E F O SC
EMMI
FE RO S
H A RP S
SO FI
SU SI
TIMMI2
WFI
28
135
209
189
22
239
48
53
146
0 .1 3
0 .2 0
0 .2 4
0 .2 5
0 .0 6
0 .2 1
0 .2 2
0 .1 4
0 .1 0
Paranal statistics
Mean statistics
A MBER
FL A M E S
FO RS1
FO RS2
I SA A C
M IDI
NA C O
SI N FO N I
UV ES
V I SI R
V MO S
2
48
477
297
364
15
92
10
449
5
30
0 .1 5
0 .1 2
0 .4 2
0 .3 2
0 .2 6
0 .2 2
0 .1 6
0 .0 8
0 .3 4
0 .0 1
0 .2 8
Science Highlights 2006
(326 April - September papers)
The Primordial Lithium Abundance
Lithium Isotopic Abundances in Metal-Poor Halos Stars
Asplund et al. Ap.J. (June 10 - UVES)
First stars VII. Lithium in extremely metal poor dwarfs
Bonifacio et al. astro-ph (October 9 - UVES)
The Mass Assembly of Galaxies
3D spectroscopy with VLT/Giraffe. I. The true Tully-Fisher relationshif at z0.6
Flores et al. A&A (June - GIRAFFE)
SINFONI Integral Field Spectroscopy of z2 UV-Selected Galaxies: Rotation
Curves and Dynamical Evolution
Foerster Scheriber et al Ap.J. (July 10 - SINFONI)
The rapid formation of a large rotating disk galaxy three biliion years after the
Big Bang. - Genzel et al. Nature, (August 17 - SINFONI)
The VIMOS VLT Deep Survey: Evolution of the luminosity functions by galaxy
type up to z=1.5 from first epoch data.
Zucca et al. A&A (September; VIMOS)
Themes
A probable stellar solution to the cosmological lithium discrepancy
Korn et al. Nature (August 10 - FLAMES+UVES)
The Galactic Center
The Two Young Star Disks in the Central Parsec of The Galaxy: Properties,
Dynamics, and Formation. - Paumard et al. Ap.J., (June 1 - SINFONI)
Variations in the Spectral Slope of Sagittarius A* during a Near-Infrared Flare
Gillessen et al. Ap. J., (April 1 - NACO)
Clockwise Stellar Disk and the Dark Mass in the Galactic Center
Beloborodov et al. Ap.J. (Septermber 1)
The flare activity of Sagittarius A* - Eckart et al. A&A, (April - NACO)
K-band polarimatry of an Sgr A* flare with a clear sub-flare activity
Meter et al. A&A (astro-ph/0610147 - NACO)
Near-infradrd polarimetry setting constraints on the orbiting spot model for Sgr A*
flares. - Meyer et al. A&A (astro-ph/0610104 - NACO)
Cosmic Variation of the Fundamental Constants of Physics
Indication of a Cosmological Variation of the Proton-Electron Mass Ratio Based on Laboratory
Measurement and Reanalysis of H2 Spectra
Reinhold et al. Phys. Rev. Letters, (April 21 - UVES)
Most precise redshift bound to /. - Levshakov et al. A&A, (April - UVES)
Variation of the fine-structure constant: very high resolution spectrum of QSO HE 0515-4414. Chand et al. A&A, (May - UVES)
Themes
Polarimetry of near-infrared flares from Sagittarius A*
Eckart et al. A&A. (May - NACO)
The GRB - Supernova connection
Supernova 2006aj and the associated X-ray Flash 060218
Sollerman et al (A&A 454)
The assicuation of GRB060218 with a supernova and the evolution of the
shockwave - Campana et al (Nature, August 31)
Optical observations of GRB 060218/SN 2006aj and its host galaxy
Ferrero et al. (astro-ph)
Extrasolar Planets
An extrasolar planetary system with three Neptune-mass planets
Lovis et al. Nature, (May 18 - HARPS)
Abundance ratios of volatile vs. refractory elements in planet-harbouring stars:
hints of pollution? - Ecuvillon et al. A&A, (April - CORALIE+FEROS)
Abundaces of refractory elements in the atmospheres of stars with extrasolar
planets - Gilli et al. A&A, (449 - FEROS+UVES+other)
Discovery of a Young Planetary-Mass Binary
Jayawardhana & Ivanov Science, (September 1 - FORS2+ISAAC)
Anatomy of a Flaring Proto-Planetary Disk Around a Young Intermetiate-Mass Star
Lagage et al. ScienceExpress, (September 28 - VISIR)
Themes
The GRB 060218/SN 2006aj event in the context of other gamma-ray burst
supernovae - Ferrero et al. (A&A, 457)
Primordial Lithium Abundance
Asplund et al. (ApJ)
Korn et al. (Nature)
Primordial Lithium Abundance
Model: Richard, Michaud & Richer (2005)
Bonifacio et al. (A&A preprint)
Conclusions
 The
gap between the Spite plateau and the Big-Bang
Nucleosynthesis model predictions is still a challenge both
observationally and theoretically.
 Pre-galactic production of both Li(6) and Li(7) through the
decay of a massive primordial particle, such as the
Gravitino, remains one of the most attractive candidates.
 Diffusive depletion of surface Li can explain the (7)Li gap,
but may be in conflict with the photometric temperature
scale. Determination of Teff to 50K is required. Interesting
challenge for the VLTI?
The Mass Assembly of Galaxies
Flores et al. (A&A)
The Mass Assembly of Galaxies
Flores et al. (A&A): GTO program with FLAMES IFUs
The Mass Assembly of Galaxies
Weiner et al. (astro-ph/0609091): 1000 Galaxies to z=1.2 with Keck
UV-selected galaxies at z>2
Summary
Specific angular momentum consistent with
that of late-type galaxies in the local
universe.
Disks are thick and have v/ ratios about 10
times lower than local disk galaxies.
Foerster Schreiber et al. (ApJ): SINFONI
BzK-15504: A large protodisk galaxy at z=2.4?
Genzel et al. (Nature): SINFONI
A large protodisk galaxy at z=2.4
Summary
The strong deviations (a-c) from a simple
rotation pattern indicate a (70-100km/s) radial
component.
A large, massive protodisk is channelling gas
towards a growing bulge hosting an accreting
massive BH.
Star formation in the disk with no evidence for
a major merger
Conclusions
• Integral-Field spectrographs such as FLAMES, VMOS, and SINFONI
are already having a large impact on understanding the massassembly of galaxies in the Universe
• The T-F relation seems to develop already at redshifts z>2, although
it is still not clear whether rotation of z=2 galaxies is due to mergers or
to disks. The case of BzK-15594 observed with SINFONI in AO mode
indicates the rapid formation of rotating stellar disk possibly followed
by the formation of a Bulge from disk instabilities.
• The evolution of the Tully-Fisher relation since z=1.2 is still
controversial and much larger samples of IFU data would be required
to understand the impact of photometric miss-alignments in the
existing slit data.
The Center of our Galaxy
There is a cluster of B stars in the central 1’’ of the galaxy, the so-called S-cluster. These high
proper motion stars - in particular star S2 - show that Sgr A* is a black-hole of 3-4 million solar
masses.
Large numbers of young stars, in particular O supergiants and WR stars are observed within 20’’
of the black-hole.
Surprinsingly, therefore, massive star formation has occurred near or at the Galactic Center within
the past few million years. The most promissing explanations for this are:
1. Stars have formed in-situ out of the fragmentation of a very dense gas disk
2. The young stars come from an in-spiralling massive (M>100,000Msun) star cluster
The formation of the central S-cluster of >15 B stars in the central light month may result from a
the scattering of stars from the reservoir of massive, young stars further out.
The black-hole itself is very faint at IR and is observed to flare.
The Central Cluster
Paumard et al Ap.J..
The Central Cluster
The Central Cluster
=
Clockwise disk
=
Counterclockwise disk
=
Ionized mini-spiral
=
CND molecular gas
=
The northern arm
The Central Cluster
Summary
The large majority of early
type stars in the central
parsec reside in one of two
pretty flat (H/r=14%) rotating
disks
The disks have well defined
inner edges (1’’ for CWS).
CCWS resembles a ring
The stellar disks are coeval
within 1Myr with ages 6+/-2
Myr. They must have formed
in less than 2Myr.
The total mass of these disks
does not exceed 10000 Msun.
Sagittarius A*
Typical duration: 100 min
4+/-2 per day
Sagittarius A*
HKL - Eckart et al. A&A
Sagittarius A*
Eckart et al A&A - NACO K-band
Sagittarius A*
Summary
Flares of typical duration 60-100 min apear about
2-6 times per day.
The IR emission from these flares is strongly
polarized (>50%)
Polarized IR emission clearly shows quasi-periodic
sub-flares with a periodicity of about 20min
NIR and X-ray flares appear simultaneously to
within the time resolution of observations
The observations are in agreement with a combined
hot spot/ring model. Highly polarized blobs of
plasma orbiting the BH close to the horizon are
responsible for the 20m quasi-periodic sub-flares
(implying a spin parameter a>0.5 for the BH). The
flares are due to sound waves propagaring
azimuthally along the ring.
Meyer et al. (a,b) A&A astro-ph
Conclusions
I
The central few parsecs of the Galaxy display most of the
properties observed in AGN, but at a distance of only 7.6
kpc allowing exquisitly detailed investigations of the nuclear
stellar populations, the nuclear accretion disk, and the
properties of the central Black-Hole.
At least part of the young massive stars at the GC appear to
have formed in-situ from a dense accretion disk. The disk
has a hole in the center exactly where the S-stars are found.
The size of this hole (1’’) agrees well with the size of the
region where star formation is not expected. The origin of
the CCWS disk is not so clear, and could be due to the infall
of a very dense cluster, or to in-situ star formation.
The accretion of gas onto the BH is weak and powers flares
arising from blobs of plasma near the last stable orbit
around the BH. The emission is well modelled by SSC
processes.
Quasi-periodic flares akin to those observed in massive Xray binaries. These sub-flares show a periodicity of about
20min and may arise from a jet.
VLT is clear leading this field.
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