Andrea Ghez (UCLA)
Title: The Galactic Center
Abstract: I will review recent progress on our Galactic Center program, which is
aimed at demonstrating the existance of a supermassive black hole in the center
of our Galaxy and understanding its environs. This will include
the latest oribtal analysis of astrometric and radial velocities
measurements of individual stars, which provide estimates of the
black hole's mass, position, distance and velocity as well as limits on any
other possible extended mass distribution. This experiment has provided the
best evidence yet, for the existance of a supermassive black hole at the
center of a normal type galaxy. In addition, recent thermal
infrared imaging has revealed variability on short timescales, a likely
signature of hot plasma within only tens of Schwarzchild radii of the
event horizon. OSIRIS will provide an exciting next phase of this experiment.
Antonin Bouchez, David Le Mignant (WMKO)
Title: Got an AO guide star brighter than R=19?
Abstract: Commissioning and optimization of the Keck Laser Guide Star AO system has
progressed rapidly since first light one year ago, and shared-risk science
observations begin in November 2004. We will present a brief review of
current instrument performance (delivered Strehl and corrected field of
view) as well as typical PSF profiles using tip-tilt guide stars as faint as
R=19. The instrument has already demonstrated great scientific potential:
We will present early engineering science observations of several targets,
including high quality images (75% Strehl!) of a very bright 3.8 micron
flare from the black hole at the galactic center.
Dawn Erb (Caltech)
Title: Dynamical and Stellar Masses of Star-forming Galaxies at z~2
Abstract: We have assembled a sample of several hundred star-forming galaxies at
z~2, selected by their rest-frame UV colors and with spectroscopically
confirmed redshifts. We use NIRSPEC H-alpha spectra of ~100 of these
galaxies to determine dynamical masses and metallicities. In addition we
use UGRJK photometry to model their stellar populations and masses. We
compare their stellar and dynamical masses, and test for correlations
between the rest-frame optical luminosity, H-alpha line widths and nebular
chemistry. The sample shows considerable diversity in mass, age and
metallicity.
Tommaso Treu (UCLA)
Title: The black-hole mass velocity dispersion relation at z~0.37
Abstract: We present the first results from a comprehensive program to measure
directly the evolution of the black-hole mass velocity dispersion
relationship, and thus to map the co-evolution of black-holes and
spheroids. The program uses a combination of telescopes (Keck, Lick,
HST) and techniques (empirically calibrated photo-ionization,
reverberation mapping, stellar absorption lines analysis) to determine
the observables to the highest possible level of accuracy and
redundancy. A first black-hole mass velocity dispersion relationship
at z~0.37 based on Keck data will be presented.
Crystal Martin (UCSB)
Title: Cool Winds and Hot Winds: Are They Compatible?
Abstract: Interstellar gas kinematics measured from resonance absorption
lines in ESI and HIRES spectra have been used to reassess the
dependence of galactic outflow speeds on starburst luminosity and
galactic mass. These cool outflows are found to be faster in more
luminous starbursts, which is surprising since the \x temperatures
of the hot wind component show little variation with galactic mass.
I will show, however, that these two observations actually are
consistent with the traditional dynamical model for galactic winds.
These supernova-powered winds do not, however, naturally predict
the observed correlation between terminal wind velocity and galactic
escape velocity. I will argue that radiation pressure contributes
to the acceleration of the cool wind and that an effective galactic
Eddington luminosity could explain the observed correlation.
Nate McCrady (UC Berkeley)
Title: The IMF in M82 Super Star Clusters, A Population Study
Abstract: The nuclear starburst in M82 is host to over 20 infrared-bright, dense,
young superstar clusters (SSCs). We use high-resolution NIRSPEC
spectroscopy to measure the stellar velocity dispersions and HST NICMOS &
ACS images to measure halflight radii and integrated luminosities. We
calculate Virial masses for the SSCs, and compare light-to-mass ratios to
population synthesis models to constrain the IMF for individual clusters.
With a sample of over 20 clusters, this dataset represents the largest
study of SSCs in a single galactic environment, providing a strong test of
environmental dependency of the IMF.
Imke de Pater (UC Berkeley)
Title: Keck AO Observations of Uranus and Neptune and their ring systems
Abstract: We have observed Uranus and Neptune with the Keck AO system
since 2000. The system has improved dramatically in recent
years (M. van Dam), which is particularly apparent in
observations of Uranus. We show results from both before and after AO
optimization. Images in July 2004 reveal the first high-altitude
convective cloud activity ever seen in Uranus' southern
hemisphere. They also show the detection of a broad sheet
of material (1986U2R) inside the main ring system, seen only
once before during the 1986 Voyager flyby. Our results on Neptune's
ring arcs are equally dramatic, revealing that the leading
arcs have almost disappeared since Voyager imaged them in 1989.
Mate Adamkovics (UC Berkeley)
Title: Titan: Visualization and Analysis of Spectral Image Data Cube at 1.4 -
1.8 micron
Abstract: We assembled spectral image datacubes of Titan in H-band with
AO/NIRSPEC, by stepping the spectrometer slit across Titan's disk. We
constructed images of Titan at each wavelength, i.e., essentially
simulated an image datacube as would be obtained from OSIRIS. With
this method one can characterize Titan's atmosphere over the entire
disk, in more specific vertical detail than possible with either
narrowband imaging or slit spectroscopy at one position. At the
shorter wavelengths we see the surface with its bright and dark
terrain, while at longer wavelengths we probe different atmospheric
levels. The data have been assembled into a movie, showing the surface
and different atmospheric levels while stepping up in altitude. We use
a radiative transfer code to analyze the data.
Tom Greene (NASA Ames)
Title: Astrophysical properties of accreting low mass protostars: results
of a NIRSPEC survey
Abstract: We have determined the basic astrophysical properties of a sample of
42 Class I and flat spectrum low mass protostars in the nearby rho
Oph, Ser, Tau, and other dark clouds by fitting their 2 micron
NIRSPEC spectra (R=18,000) to spectra synthesized from NEXTGEN models.
The effective temperatures, surface gravities, and stellar luminosities
of these objects are similar to those of classical T Tauri stars.
Few current pre-main-sequence models contain the appropriate physics
(i.e. accretion) to represent these objects, so their masses and
especially their ages cannot be determined accurately from H-R diagrams.
However, theses protostars have higher IR veiling and rotation velocities
than T Tauris, likely due to significant mass accretion. This is the
first spectroscopic study which has yielded statistically significant
information on the astrophysical properties of accreting protostars.
James Rhoads (STScI)
Title: Lyman-alpha Galaxies
Abstract: Lyman alpha emission offers an efficient way of identifying galaxies
at high redshifts and faint bolometric luminosities. We present DEIMOS,
LRIS, and Gemini GMOS spectroscopy of 80 Lyman alpha galaxies identified
in our Large Area Lyman Alpha (LALA) survey. Our spectroscopic
confirmation rate is about 75%. Both individual and composite
spectra suggest that the Lyman alpha emission is powered by star
formation and not AGN. Comparing the luminosity functions of
Lyman alpha galaxies at z=6.5 and at lower redshifts shows a
general consistency, which disfavors a neutral IGM.
Jason S. Kalirai (UCSC)
Title: The Initial-Final Mass Relation
Abstract: The initial-final mass relationship relates the mass of a white
dwarf to its main sequence progenitor. The relationship, despite being poorly
constrained, is widely used as input in several important astrophysical
areas. These include determining the upper mass limit to white dwarf
production, constraining the rates of type II SNe, better understanding
star formation rates, determining the chemical enrichment of the ISM, and
constraining the birth rates of neutron stars.
We will discuss first results from a new program at Keck to investigate
the white dwarf initial-final mass relationship. Analysis of LRIS
multi-object spectroscopic observations of very faint candidate white
dwarfs in the rich, well studied, open star cluster NGC 2099 will be
presented. Preliminary results look very impressive, encouraging further
investigation into the relationship by observing both older and
younger clusters with Keck.
Ann Merchant Boesgaard (IfA/UH)
Title: New Light on the Light Elements
Abstract: The latest adventures with the trio: LITHIUM, BERYLLIUM, AND BORON
1. Add a Be dip to the Li dip in the mid-F dwarfs.
A Be dip has been discovered in the Hyades, Coma, UMa, and Praesepe clusters.
Similar to the Li dip at temperatures near 6400 - 6800 K, but not as deep as
the Li chasm.
2. No Li or Be dip in youthful clusters.
For the younger clusters, Pleiades and $\alpha$ Per, there is no depletion of
Li or Be. Implies that the depletions occur during the main sequence phase of
evolution, after some 10$^8$ years.
3. Depleted but detected: Li and Be are correlated.
For field and cluster stars in the temperature regime of 5900 - 6650 K there
is a strong correlation of Li and Be. 88 stars. slope = 0.38 +- 0.04.
Well-matched by the predictions of rotationally-induced mixing.
4. Add B to the mix: Be and B are correlated.
Some stars with severe Be depletions are found to be mildly depleted in B. 20
stars. slope = 0.15 +- 0.04. For those stars there is nary a Li atom to be
found... Well, very low upper limits. No model predictions for B - yet.
Could it be? rotationally-induced mixing?
Richard Ellis (Caltech)
Title: Searching for the Sources Responsible for Cosmic Reionization
Abstract: Surveys for the abundance of UV emitting sources beyond z=6
have been conducted by combining HST deep imaging with DEIMOS
spectroscopy. This work is complemented by more detailed studies of
individual sources boosted by strong lensing in rich clusters. First
results suggest there may be many star-forming sources in the
redshift interval 7< z < 10. An ongoing survey with NIRSPEC aims
to determine their abundance and basic characteristics.
Marc Davis (UC Berkeley)
Title: Progress with the DEEP2 survey
Abstract: The DEEP2 survey has collected ~40,000 redshifts to date,
and I shall summarize the investigations currently underway. These
include the internal kinematics
of galaxies, groups and clusters of galaxies, K+A galaxies, and more.
Furthermore one
of our fields, the EGS (Extended Groth Survey) in which we shall
deliver ~17,000 galaxy
spectra, will have coverage with the Spitzer, GALEX, HST, and Chandra
satellites. The opportunities for in depth statistical analyses are
clearly immense, and the Keck data will
be released as soon as we can assemble a complete sample.
B. T. Soifer (Caltech)
Title: Keck Observations of Spitzer/MIPS sources in the NDWFS Bootes Field
Abstract: The Spitzer/NDWFS team has conducted a MIPS survey of the 10 square degree
Bootes Field area covered by the NOAO Deep Wide Field Survey project.
We obtained Keck /LRIS and DEIMOS observations of optical counterparts
to more than 100 objects out of the 21,000 objects selected from a
complete
catalog of extragalactic sources brighter than 300 microJanskies at 24
microns.
The results from these observations will be described, including the
spectral
classifications and redshift distributions of these sources, and well as a
discussion of particularly interesting objects found in this survey.
George Helou (Caltech)
Title: Spectroscopic Follow-up of Faint Spitzer Sources Using DEIMOS and LRIS
Abstract: We have obtained redshifts for a few hundred
24-micron sources in the Spitzer First Look Survey fields. The DEIMOS
sample was largely unbiased, while the LRIS sample selection attempted
to favor unusual objects. We find significant numbers of sources
at z>2, with the highest so far at z=3.8 with AGN-like spectral
signature. There is convincing evidence that the visibility of sources
as a function of redshift reflects the spectral variations expected
from Aromatic Features and silicate absorption feature in the
5-to-15um range.
Mary Barsony (SSI/SFSU)
Title: A Mid-Infrared Imaging Survey of Embedded Young Stellar Objects in the Rho Ophiuchi Cloud Core
Abstract: We have carried out a mid-infrared imaging survey of
165 objects in the nearby Rho Ophiuchi cloud core with MIRLIN on Keck II
and Palomar, and with LWS on Keck I. We find that young stellar objects
(YSOs) spend as long a time shedding their remnant infall
envelopes (~ 3x10^5 yrs) as they do in their late-stage protostellar
phase. We find mid-infrared variability to occur in all evolutionary
stages where optically thick disks occur, and near-infrared variability
to be more common at the earlier evolutionary stages than mid-infrared
variability. Although there is a general trend of
higher NIR veiling at earlier evolutionary stages, the NIR continuum
veiling can vary widely for a single source in any SED class in which
active disk accretion can take place, highlighting the highly
time-variable nature of disk accretion. Finally, the relation between
near-IR and mid-IR continuum excesses (above photospheric) for objects
with available NIR spectroscopy will be discussed.
Sean Brittain, Terrence Rettig (Notre Dame)
Title: CO Emission and Absorption toward v1647 Ori (McNeil's Nebula)
Abstract: We present high-resolution infrared spectroscopy of v1647 Ori, which
reveals hot and cold gas phase CO, molecular hydrogen, and the
presences of ice features of CO and H2O. The emission lines of 12CO
(1-0), (2-1), and (3-2) likely originate from warm gas in an inner
accretion disk region where substantial clearing has occurred. The
width of the broad emission lines increase with increasing J-value
suggesting the hotter CO gas we are detecting is closer to the
central star. The less broadened (lower J) CO lines are indicative
of more distant and cooler material in the inner disk. Superposed on
broad emission features with low J values are narrow 12CO absorption
components typical of cold interstellar cloud material (~20K). The
absorption line results suggest that we are viewing the central star
through the cold intervening material from the L1630 cloud along our
line of sight. Model fits to the prominent H2O and CO ice profiles
are consistent with cold (<20 K) amorphous water ice (t = 0.65) and
predominantly apolar CO ice (t = 0.58). The CO and H2O ices are
unprocessed (unannealed), similar to ices found in dense clouds. The
implication is that the very cold CO absorption as well as the ices
detected along the line of sight is not directly associated with the
star or disk of v1647 Ori.
Stanimir Metchev (Caltech)
Title: Brown Dwarf Companions to Solar-Type Stars from the Palomar/Keck Adaptive
Optics Young Star Survey
Abstract: We present first results from a coronagraphic survey of young (3-500 Myr)
nearby (20-260 pc) F5-K5 stars with the Palomar and Keck AO systems. The
survey is sensitive to sub-stellar companions at separations >0.5" from
their host stars, and to planetary-mass (5-15 Mjup) objects at separations
>2". From multi-epoch astrometric and spectroscopic observations, we have
discovered an L4 sub-stellar companion to the young (0.5 Gyr) star HD
49197. The new brown dwarf is a member of a very limited list of known
young L or T dwarfs, and as such could be used to constrain evolutionary
models of ultra-cool objects. Over 200 other candidate companions
identified from first-epoch direct imaging await confirmation.
Paul Kalas (UC Berkeley)
Title: High contrast imaging of circumstellar debris disks
using NIRC2 coronagraphy
Abstract: We show the latest results from our program to
detect and characterize debris disks in scattered light using Keck
adaptive optics and NIRC2 coronagraphy.
Michael Liu (IfA/UH)
Title: Substructure in the Disk around the Young Star AU Mic (GJ 803)
Abstract: We present the first direct imaging of the inner (15-80 AU) disk of AU Mic
(GJ 803), the nearest known scattered light disk to Earth. Keck adaptive
optics imaging provides a physical resolution of 0.4 AU, resulting in the
sharpest images ever obtained of a circumstellar disk. The inner disk is
asymmetric and shows spatially localized enhancements and deficits at
~25-40 AU separations. The overall morphology points to the influence of
unseen larger bodies, resembling structures expected from recent planet
formation. AU Mic is coeval with the archetypical debris system beta
Pictoris, and the similarities between their two disks point to a
synchronous disk evolution. Multiple indications of substructure appear
to be common in circumstellar disks at an age of ~12 Myr.
Rachel Akeson (MSC/Caltech)
Title: How to observe with the Keck Interferometer
Abstract: The Keck Interferometer passed an operational review in April 2004 for
the visibility amplitude mode and is open to the Keck community for
the 2005A semester. The instrument allows observations of source
structure on scales of a few milliarcseconds.
KI is operated by the W.M. Keck Observatory and
the Michelson Science Center with service observing and full contact
science support. I will describe the current abilities of the
interferometer and some of the science topics that can be addressed.
Dennis Crabtree (NRC-HIA)
Title: Size Matters: The Scientific Impact of the Keck Telescopes
Abstract: The scientific productivity and impact, as measured by citations,
of the Keck telescopes will be discussed. A comparison with several other
ground-based telescopes and HST indicate that the Keck Observatory has
profoundly different influence on the scientific community.
R. Michael Rich (UCLA)
Title: Abundances of Galactic bulge stars
Abstract: Over the past few years, we have observed 27 bulge K giants in the
optical using HIRES, and 10 bulge M giants using NIRSPEC. Using
optical spectra with resolution as high as R=67,000 we have settled
on what we believe to be a definitive iron abundance scale for the
bulge, settling a long standing controversy that has been fueled by
the dificulty of obtaining abundances for metal rich stars. The
M giants are generally metal rich, and shown to have enhanced alpha
elements relative to M giants in the Solar vicinity. We conclude
that the chemistry of the bulge is consistent with a rapid formation
timescale and enrichment by Type II SNe.
Mike Beasley (UCO/Lick)
Title: Globular Clusters in M31: The view from Keck
Abstract: We present recent results based upon Keck/LRIS spectroscopy of
globular clusters in the Andromeda spiral (M31).
We have found that, unlike the Milky Way, M31 hosts
a significant disk population of young, metal-rich globular
clusters in addition to a halo-like population of
intermediate-aged, intermediate-metallicity GCs.
The implications for the formation history of this
Galaxy are discussed.
Alan Stockton (IfA/UH)
Title: Old Massive Disks at High Redshifts
Abstract: We have been investigating galaxies with photometric
evidence for old stellar populations found in the fields of powerful
radio sources. A significant fraction of such galaxies show light
distributions that are dominated by exponential profiles and are likely
to be massive disk systems. I will discuss three such galaxies for
which we have fairly detailed observations from the Keck and Subaru
telescopes, as well as the implications of the presence of such
galaxies early in the history of the universe and their possible origin
and fate.
S. R. Kulkarni (Caltech)
Title: Gamma-ray Bursts: Lighthouses
Abstract: In a situation reminiscent of quasars in the sixties, gamma-ray bursts
(GRBs) are gradually being exploited to study the intergalactic
medium, the build up of elements and identify cosmological star-forming
galaxies. The Keck Observatory has been a dominant engine in these
exploitations and the speaker will summarize the current situation and
conclude that GRBs (thanks to the imminent launch of Swift) are poised
to make pre-eminent contributions to the above areas of enquiry.
James Larkin (UCLA)
Title: OSIRIS: The Next Keck Instrument
Abstract: OSIRIS is an integral field spectrograph designed for the Keck Adaptive
Optics System. It is currently undergoing final testing at UCLA.
Commissioning will occur in late 2004 and early 2005 with first community
access in late 2005a. I will describe the instrument and present some of
the latest test results to help astronomers begin planning their observing
programs.
Bob Goodrich (WMKO)
Title: Observing Support at Keck: What we are doing for you
Abstract: The Observing Support group at Keck continues to try to streamline
operations and make more time available to observers. Of the many tools
we use to accomplish this, I will discuss the duty-cycle metrics
system, and the "E-TAC" (E for engineering). The duty-cycle metrics
system is used to quantify the effects of instrument and telescope
improvements, with the goal of maximizing the amount of time available
for taking science data. An outline of the system will be given, along
with some results of how recent instrument repair missions have fared.
The E-TAC adds structure to the use of engineering time, requiring
well-justified proposals and identifying unneeded engineering time
early enough that it can be given back to science.
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