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Contribution List

Displaying 58 contributions out of 58
Session: Session 1D
Track: Earth's atmospheric effects
The ability of type Ia supernova surveys to distinguish among the various proposed theories of dark energy is presently limited by the need to reduce systematic photometry errors to significantly less than 1%. In pursuit of this goal, Stubbs and Tonry (2006) have proposed an approach to photometric calibration that deemphasizes celestial standards in favor of using a NIST-calibrated photodiode as ... More
Presented by Maxwell FAGIN on 16 Apr 2012 at 4:00 PM
Type: Paper Session: Session 3C
The UNM Measurement Astrophysics group is currently constructing and testing a mobile instrument suite that includes a multi-wavelength backscatter lidar, stellar spectroradiometer and cameras (visible and thermal infrared) that will provide real-time atmospheric transmission metadata in the column of atmosphere through which the supported telescope is observing. The design, operation and calibra ... More
Presented by Prof. Peter ZIMMER on 18 Apr 2012 at 2:00 PM
Type: Paper Session: Session 4C
ACCESS, Absolute Color Calibration Experiment for Standard Stars, is a series of rocket-borne sub-orbital missions and ground-based experiments that will enable improvements in the precision of the astrophysical flux scale through the transfer of absolute laboratory detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calib ... More
Presented by Dr. Mary Elizabeth KAISER on 19 Apr 2012 at 2:30 PM
Session: Session 1D
Track: Calibration of instruments/telescopes before and after deployment
I will present an overview of our ongoing efforts to ascertain (through direct measurement) the both instrumental response function and the variable aspects of atmospheric transmission, in the context of surveys such as PanSTARRS and LSST. We have now gained experience with the use of tunable lasers and NIST-calibrated photodiodes to ascertain the instrumental response function from multiple teles ... More
Presented by Prof. Christopher STUBBS on 16 Apr 2012 at 3:30 PM
Session: Session 2C
Track: Calibration of instruments/telescopes before and after deployment
The goal of amplitude and flux calibration at millimeter and submillimeter wavelengths is to convert the output voltage or counts from a telescope spectrometer into brightness temperature or flux density. Because the adverse effects of instrumental and atmospheric variations of the detected amplitude grow rapidly with frequency, standard calibration procedures used at longer radio wavelengths are ... More
Presented by Dr. Jeff MANGUM
Type: Paper Session: Session 2C
Track: Large Surveys and Missions (Sub-mm and Radio)
In order to address deficiencies in the flux density scale used in most radio astronomy observations (Baars et al. 1977), we have carried out observations of the so-called "secondary calibrators" from that paper over the past 28 years with the Very Large Array. To establish an absolute flux density scale from 1 to 50 GHz, we use the emission from Mars at frequencies above 5 GHz, and the Baars sca ... More
Presented by Bryan BUTLER on 17 Apr 2012 at 2:00 PM
Session: Session 4A
on 19 Apr 2012 at 8:45 AM
Session: Session 2A
on 17 Apr 2012 at 8:45 AM
Session: Session 3A
on 18 Apr 2012 at 8:45 AM
Type: Paper Session: Posters
A statistical-parallax analysis of the sample of Chen at al. (2010), which the authors purport to consist mostly of red horizontal-branch stars selected based on SEGUE spectroscopy, shows that the luminosities of the stars of this sample are overestimated, on average, by ~2 mag in terms of absolute magnitude. This result implies that the sample actually consists mostly of main-sequence and turnoff ... More
Presented by Andrei DAMBIS on 16 Apr 2012 at 5:10 PM
Type: Paper Session: Session 3B
We compare bona fide ncalibrated mean (VI)C magnitudes of several thousand stars found in the CCD frames taken during our photometric observations of Cepheids and RR Lyrae type stars at the South African Astronomical Observatory with the corresponding mean (VI)C magnitudes measured in the course of the ASAS survey to assess the quality of ASAS photometry and derive the appropriate transformation ... More
Presented by Dambis DAMBIS
Session: Session 2D
Track: Calibration of instruments/telescopes before and after deployment
The Physics of the Accelerating Universe (PAU) Survey, being carried out by several Spanish institutions, will image an area of 100-200 square degrees in 6 broad and 40 narrow band optical filters. The narrow band filters will each cover 100 Angstroms, with the set spanning 4500-8500 Angstroms. The broad band set will consist of standard ugriZy filters. The team is building a camera (PAUCam) wh ... More
Presented by Anne BAUER on 17 Apr 2012 at 4:40 PM
Session: Session 3C
Track: Impact of calibration errors on astrophysics parameters
With around 1 thousand type-Ia supernovae populating the Hubble diagram, the uncertainty of the photometric calibration of the survey now limits the precision of the cosmological parameters. We first present the method used to establish a uniform photometric response of the MegaCam instrument from CFHT used for SNLS. We then present a joint effort of the SNLS and SDSS collaborations to merge t ... More
Presented by Dr. Marc BETOULE on 18 Apr 2012 at 2:40 PM
Type: Poster Session: Session 2C
Signal calibration at millimeter and submillimeter wavelengths requires the correction of amplitude and phase irregularities at several levels in an observatory system. Measurement calibration of the Atacama Large Millimeter Array (ALMA) requires that the signal amplitude, phase, and polarization be monitored for stability and purity. Instrumental bandpass, antenna positioning, antenna location, ... More
Presented by Dr. Jeff MANGUM on 17 Apr 2012 at 1:00 PM
Session: Session 3B
Track: Archiving of calibration data
The AAVSO Photometric All-Sky Survey (APASS) has been underway for over a year. This survey will calibrate the entire sky from 10<V<17 in five filters: Johnson B and V, and Sloan g',r' and i'. Each area of the sky is visited four times during the course of the survey, with two visits at one field center and two visits at a field located center-to-corner from the first so as to have maximum overl ... More
Presented by Arne HENDEN on 18 Apr 2012 at 11:00 AM
Session: Session 2A
Track: Large Surveys and Missions (Sub-mm and Radio)
The Herschel Space Observatory has the largest aperture of any space telescope, with a primary mirror of 3.5 metres in diameter. The telescope is radiatively cooled to below 90K, allowing it to be used for far-infrared and sub-millmetre observation. It has three cryogenically cooled focal plane instruments that cover the wavelength range of 55 to 670 microns. These allow broad-band photometry at 6 ... More
Presented by Dr. Anthony MARSTON on 17 Apr 2012 at 10:00 AM
Type: Paper Session: Session 4C
J-PAS survey consists of an 8000 square degree photometric sky survey with a set of 52 narrow-band and 2 broad-band filters. The main goal is to produce a photo-redshift catalog of ~15 millions red, early-type galaxies with a precision σ(z)~0.003(1+z) to measure the Baryonic Acoustic Oscillation (BAO).Such precision requires specific care in the photometric calibration survey. This contribution p ... More
Presented by Dr. Nicolas GRUEL on 19 Apr 2012 at 3:10 PM
Type: Paper Session: Session 4A
Skymapper is a survey of the sky south of the equator in 6 bands, u,v,g,r,i,z. SkyMapper's griz bands are similar to those of SDSS while the u band is similar to Stroemgren u, and the v band is similar to DDO 38. It will be conducted over 5 years commencing in late 2012. The first year will concentrate on a shallow coverage (g=8 to 18 mag) of the whole area in photometric weather to provide standa ... More
Presented by Prof. Mike BESSELL on 19 Apr 2012 at 10:00 AM
Session: Posters
Track: Intercalibration between systems
We summarize plans to monitor, calibrate and validate photometric observations with our autonomous, robotic network of 2m, 1m and 40cm telescopes. These are sited globally to optimize our ability to observe time-variable sources. Wide field "context" cameras aligned with our network telescopes cycle through BVriz filters spanning our optical range every ~2 minutes, measuring instantaneous throu ... More
Presented by Dr. Andrew PICKLES, Prof. Wayne ROSING on 16 Apr 2012 at 5:10 PM
Session: Session 1B
Comments will be made on situations encountered in the process of observational optical photometry and the establishing of standard star sequences.
Presented by Dr. Arlo LANDOLT on 16 Apr 2012 at 10:30 AM
Session: Session 4D
Presented by Dr. Susana DEUSTUA on 19 Apr 2012 at 4:15 PM
Session: Posters
Thermal soft X-ray emission is detected from many hot hydrogen-rich white dwarfs (spectral type DA) with an effective temperature in excess of 20 000 K. Most of the objects with effective temperatures < 40 000 K have virtually pure hydrogen atmospheres while the majority of the hotter ones emit X-ray fluxes lower than predicted by hydrogen model atmospheres and therefore must contain heavier eleme ... More
Presented by Dr. Thomas RAUCH on 16 Apr 2012 at 5:10 PM
Session: Session 1D
Track: Calibration of instruments/telescopes before and after deployment
DECal is a new spectrophotometric calibration system for the CTIO Blanco 4 meter telescope. It is currently being installed as part of the Dark Energy Survey. The system uses a tunable light source to measure the wavelength-dependent instrumental response function of the total telescope+instrument in the range 300<λ<1100nm. The calibration will be performed regularly to monitor changes in telesc ... More
Presented by Dr. Jennifer L. MARSHALL on 16 Apr 2012 at 4:20 PM
Type: Paper Session: Session 2B
The International Astronomical Consortium for High-Energy Calibration (IACHEC) aims to provide standards for high energy calibration and supervise cross-calibration between different X-ray and Gamma-ray observatories. This goal is reached through Working Groups, involving around 40 astronomers worldwide. In these Groups, IACHEC members co-operate to define calibration standards and procedures. The ... More
Presented by Dr. Herman MARSHALL on 17 Apr 2012 at 11:00 AM
Type: Paper Session: Session 1C
Track: Earth's atmospheric effects
TBD (Invited Talk)
Presented by Dr. Bruce WIELICKI on 16 Apr 2012 at 1:00 PM
Type: Paper Session: Session 2B
Imperfect calibration of galaxy surveys due to either astrophysical or instrumental effects leads to biases in measuring galaxy clustering. These systematics in turn affect cosmological parameter measurements. More interestingly (and disturbingly), the spatially varying calibration errors also generically lead to violations of statistical isotropy of the galaxy clustering signal. Here I present pr ... More
Presented by Dr. Dragan HUTERER on 17 Apr 2012 at 11:30 AM
Session: Session 3C
Track: Impact of calibration errors on astrophysics parameters
Experience with the SDSS calibration applied to SDSS SN will be described.
Presented by John MARRINER on 18 Apr 2012 at 2:20 PM
Type: Paper Session: Session 4C
Track: Large Surveys and Missions (UV/Optical/NIR)
Hubble’s Next Generation Spectral Library (NGSL) consists of R~1000 spectra of 374 stars of assorted temperature, gravity, and metallicity. Each spectrum covers the wavelength range, 0.18-1.00 μ. The library can be viewed and/or downloaded from the website, http://archive.stsci.edu/prepds/stisngsl/. Stars in the NGSL are now being used as absolute flux standards at ground-based observatories. ... More
Presented by Dr. Sara HEAP on 19 Apr 2012 at 2:00 PM
Presented by Dr. Elena PANCINO
Session: Session 3A
Presented by Dr. Ronald HOLZWARTH on 18 Apr 2012 at 9:00 AM
Type: Paper Session: Session 1C
Earth’s atmosphere is a wavelength-, direction-, and time-dependent turbid medium through which all ground-based telescopes observe. Transmission through the atmosphere is a significant source of systematic radiometric error which can best be obviated by direct, real-time measurements of the column of atmosphere through which a telescope is observing. Using weather and imaging radiometric data w ... More
Presented by John MCGRAW on 16 Apr 2012 at 2:20 PM
Type: Paper Session: Session 4C
We have made several significant improvements to the final cryogenic calibration of the IRAC instrument aboard the Spitzer Space Telescope. The final calibration uses the ensemble of calibration data collected over the five-plus years of the cryogenic mission and includes knowledge obtained on intrinsic photometric variations. Photometric variation with location on the array and phase of stellar ... More
Presented by Dr. Sean CAREY on 19 Apr 2012 at 2:50 PM
Session: Session 1A
Presented by Dr. Douglas TUCKER on 16 Apr 2012 at 8:50 AM
Type: Paper Session: Session 3B
One of the most important tasks of the Lyra mission is to create a dense all-sky grid of high-precision photometric standards. The total number of standards should be on the order of several million, and to achieve this goal, more than 300 million stars will be measured in the course of the mission. The system must contain standards in all ranges of magnitudes from the brightest stars down to 16 ... More
Presented by Dr. Aleksey MIRONOV, Andrei DAMBIS on 18 Apr 2012 at 11:20 AM
Session: Posters
The German Astrophysical Virtual Observatory (GAVO) provides the registered Virtual Observatory (VO) service TheoSSA (Theoretical Stellar Spectra Access, http://dc.g-vo.org/theossa). It is dedicated to the easy access of VO users to theoretical stellar spectral energy distributions, calculated with any model-atmosphere code. We show examples for TheoSSA in operation.
Presented by Dr. Thomas RAUCH on 16 Apr 2012 at 5:10 PM
Session: Session 1A
Track: Earth's atmospheric effects
Monitoring the actual atmospheric conditions under which observations are being conducted is a key task of any ground-based observatory. At ESO’s La Silla Paranal observatory parameters like seeing, extinction and coherence time are regularly measured and the observed values are routinely used to make real-time scheduling decisions for service mode based on user-provided constraints. This effort ... More
Presented by Dr. Florian KERBER on 16 Apr 2012 at 9:30 AM
Session: Session 4C
Track: Intercalibration between systems
Theoretical spectral energy distributions (SEDs) of white dwarfs provide a powerful tool for cross-calibration and sensitivity control of instruments from the far infrared to the X-ray energy range. Such SEDs can be calculated from fully metal-line blanketed non-LTE model-atmospheres that are e.g. computed by the Tübingen Non-LTE Model-Atmosphere Package (TMAP) that has arrived at a high level ... More
Presented by Dr. Thomas RAUCH on 19 Apr 2012 at 1:00 PM
Type: Paper Session: Session 2D
Track: Large Surveys and Missions (General)
The Dark Energy Survey (DES) is a 5000 sq deg grizY imaging survey to be conducted using a 3 sq deg (2.2deg-diameter) wide-field mosaic camera (the DECam) on the CTIO Blanco 4-m telescope. The DECam is currently in the process of installation and commissioning on the Blanco, with DES operations expected in the second half of 2012. The primary scientific goal of the DES is to constrain dark energ ... More
Presented by Douglas TUCKER on 17 Apr 2012 at 3:30 PM
Type: Paper Session: Session 4B
The Large Synoptic Survey Telescope (LSST) is a next-generation optical astronomy survey facility currently under development. First light is anticipated in 2018, with survey operations officially beginning around 2021. The primary science drivers for the LSST are to understand the nature of dark energy and dark matter, to inventory the small bodies of the solar system (including Potentially Hazar ... More
Presented by Dr. Lynne JONES, Dr. Tim AXELROD on 19 Apr 2012 at 11:30 AM
Type: Paper Session: Session 2C
The Kilo Degree Survey will cover 1500 sq.deg. in Sloan u, g, r, and i using the OmegaCAM camera on the VST, at ESO Paranal. It is an ESO Public Survey that started October 15, 2011. Its main science driver is dark matter and energy from weak lensing analysis. Photometric calibration of OmegaCAM is based on the combination of (i) a very stable dome calibration unit, (ii) 3 times per night observat ... More
Presented by Dr. Gijs VERDOES KLEIJN on 17 Apr 2012 at 2:30 PM
Type: Paper Session: Session 2D
Track: Large Surveys and Missions (General)
The Dark Energy Survey (DES) will be taking the next step in probing the Dark Energy and understanding of the physics of cosmic acceleration. A step towards the photometric calibration of DES, is to have a quick, bright survey in the DES footprint (PreCam), using a prototype of Dark Energy Camera (DECam) CCDs and DES filter set. The objective of PreCam Survey is to create a network of calibrated ... More
Presented by Dr. Sahar ALLAM on 17 Apr 2012 at 4:20 PM
Type: Paper Session: Session 2D
The Dark Energy Survey (DES) is designed to measure with unprecedented accuracy the time-independent and time-dependent parameters of the Dark Energy Equation of State. Utiliziing the Dark Energy Camera (DECam), DES will scan 1/4 of the southern hemisphere in order to detect millions of faint galaxies and thousands of supernovae. In order to measure the brightnesses of these objects accurately, ... More
Presented by Dr. Kyler KUEHN on 17 Apr 2012 at 4:00 PM
Session: Session 1D
Track: Intercalibration between systems
Understanding the properties of dark energy via SNIa will require unprecedented photometric precision. Laboratory and solar photometry and radiometry regularly achieve precisions on the order of parts in ten thousand, but photometric calibration for non-solar astronomy presently remains stuck at the percent or greater level. We discuss our project to erase this discrepancy, and our steps toward ... More
Presented by Prof. Justin ALBERT on 16 Apr 2012 at 4:40 PM
Session: Session 3C
Track: Overview
I will discuss NIST's effort to create a catalog of SI-traceable spectrophotometric standard stars. Our work builds on advances in optical metrology and atmospheric monitoring made since the previous set of ground-based calibrations were done roughly thirty years ago. NIST's state-of-the art standards at visible wavelengths are now detector-based rather than source-based. I will explain how we ... More
Presented by Claire CRAMER on 18 Apr 2012 at 1:00 PM
Session: Session 3C
Track: Calibration of instruments/telescopes before and after deployment
Dark Energy studies with type Ia supernovae set very tight constraints on the photometric calibration of the imagers used to detect the supernovae and follow them up. Among the key challenges is the measurement of the shape and normalization of the instrumental throughput. In particular, it is absolutely vital to control the flux intercalibration of the imager passbands. The DICE system was ... More
Presented by Dr. Nicolas REGNAULT on 18 Apr 2012 at 3:00 PM
Type: Paper Session: Session 4D
Track: Earth's atmospheric effects
Mauna Kea is known for its pristine seeing conditions, but sky transparency can be an issue for science operations since some 25% of the observable nights are not photometric, mostly due to high-altitude cirrus. Since 2001, the original single-channel SkyProbe on the Canada-France-Hawaii Telescope has gathered one V-band exposure every minute during each observing night using a small CCD ... More
Presented by Jean-Charles CUILLANDRE on 19 Apr 2012 at 4:00 PM
Type: Paper Session: Session 4B
TBD
Presented by Dr. Susana DEUSTUA on 19 Apr 2012 at 11:00 AM
Session: Session 1B
Track: Intercalibration between systems
This talk presents a discussion of new and archival photometric measurements of several stars with complex spectral features, in particular the most massive stars (LBV and B[e] single and binary supergiants, WR stars, etc.). The data outline significant systematic differences between all involved systems of photometric measurement. The conclusion of this study is that objects that slowly change ma ... More
Presented by Christiaan STERKEN on 16 Apr 2012 at 11:30 AM
Type: Paper Session: Session 3A
Track: Large Surveys and Missions (UV/Optical/NIR)
The Calar Alto Legacy Integral Field spectroscopy Area (CALIFA) survey is the largest integral field spectroscopy survey to date. Its goal is to obtain optical 3D spectroscopy data over the entire optical wavelength range for a representative sample of 600 galaxies over a period of 3-4 years. As a legacy survey the data will become public and is suited to address a wide range of different fundamen ... More
Presented by Bernd HUSEMANN on 18 Apr 2012 at 10:00 AM
Type: Paper Session: Session 2A
I will describe the ESA's Gaia astrometric mission and its scientific potential, briefly reporting on the science performances. Then I will focus on the flux calibration model and on the ongoing ground-based campaign started to build the Gaia spectrophotometric standard stars grid, which requires approximately 200 stars, calibrated to a few percent with respect to Vega, and covering different spec ... More
Presented by Dr. Elena PANCINO on 17 Apr 2012 at 9:00 AM
Type: Poster Session: Posters
The GES is a wide field spectroscopic survey recently started with the FLAMES@VLT in Cerro Paranal. It will produce radial velocities more accurate than Gaia's for faint stars (down to V~18), and astrophysical parameters and abundances for ~100000 stars, belonging to all Galactic populations. 300 nights were assigned in 5 years (with the last year subject to approval after a detailed report). In p ... More
Presented by Dr. Elena PANCINO on 16 Apr 2012 at 5:10 PM
Type: Paper Session: Session 4A
The definition of a precise inertial reference frame is fundamental to the determination of the location and motion of objects in the sky (astrometry) and features on the earth (geodesy). Since most observing instruments are on the earth surface or in earth orbit, the earth rotation, motion and crustal distortions add considerable complexity to the determination of astrometric and geodetic ... More
Presented by Dr. Ed FOMALONT on 19 Apr 2012 at 9:00 AM
Type: Paper Session: Session 1A
Track: Overview
The Science of Calibration What are the most demanding science drivers for calibration? The answer to this question depends on whether we are referring to absolute calibration, differential calibration, or some variant in between. Our published data, even after calibration, retain some imprint of the instrumentation used to obtain them, yet science should not need to care about such artifacts ... More
Presented by Stephen KENT on 16 Apr 2012 at 9:00 AM
Type: Paper Session: Session 1C
Absorption by water vapor in Earth’s atmosphere is a major impediment to ground-based astronomical measurements in the near infrared (NIR). The problem is exacerbated by the fact that the concentration of water vapor in the troposphere is highly variable, and can change on very short timescales. While differential photometric techniques can partially compensate for this, precise NIR photometry ... More
Presented by Cullen BLAKE on 16 Apr 2012 at 2:00 PM
Session: Session 1A
Presented by Dr. Dan BAUER, OTHERS on 16 Apr 2012 at 8:40 AM
Session: Session 1C
Track: Earth's atmospheric effects
Traditional color and airmass corrections can achieve ~1% precision in photometric observing conditions. A major limiting factor is the variability in atmospheric throughput, which changes on timescales of less than a night. We present preliminary results for a system to monitor the throughput of the atmosphere, which should enable photometric precision when coupled to more traditional techniques ... More
Presented by Ms. Ting LI on 16 Apr 2012 at 2:40 PM
Type: Paper Session: Session 3B
Sternberg Astronomical Institute of Moscow State University is currently developing the “Lyra” space mission with the aim to conduct a multicolor photometric all-sky survey of stars from 3m to 16-17m onboard the ISS and produce a high-precision photometric catalog of stellar standards. The photometric accuracy of the catalog is expected to be 0.001-0.003m for stars brighter than 12m and 0.01m ... More
Presented by Dr. Mikhail PROKHOROV