Aavso paper Session I sunday Sunday, May 22, 2011, 9: 30 am – 12: 00 pm
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324SPICAPoster SessionEssex Ballroom324.01
Is Space-based Interferometry Dead? David Leisawitz1, D. Benford1, A. Blain2, J. Carr3, M. Fich4, J. Fischer3, P. Goldsmith5, J. Greaves6, M. Griffin7, G. Helou8, R. Ivison9, M. Kuchner1, R. Lyon1, H. Matsuo10, S. A. Rinehart1, E. Serabyn5, H. Shibai11, R. Silverberg1, J. Staguhn12, S. Unwin5, D. Wilner13, A. Wootten14, E. L. Wright15 1NASA GSFC, 2Univ. Leicester, United Kingdom, 3NRL, 4Univ. Waterloo, Canada, 5Caltech JPL, 6Univ. St. Andrews, United Kingdom, 7Cardiff Univ., United Kingdom, 8Caltech IPAC, 9UK ATC, United Kingdom, 10NAOJ, Japan, 11Nagoya Univ., Japan, 12JHU/NASA GSFC, 13CfA, 14NRAO, 15UCLA. 8:00 AM - 7:00 PM Essex Ballroom In the wake of the Decadal Survey and a January 2011 meeting of NASA’s Exoplanet Exploration Program Analysis Group (ExoPAG), one might be tempted to conclude that space interferometry is dead. We explain why this slogan is hyperbole, summarize the steps currently being taken to prepare for a space-based far-IR interferometer, and reiterate the science case for an imaging and spectroscopic interferometer - SPIRIT - that would operate in space at long infrared wavelengths. Space-based interferometry is alive and well, but the center of activity has shifted to a spectral region (25 to 400 microns) in which no alternative measurement technique can provide information essential to answering several scientific questions deemed compelling by the Decadal Survey. Astrophysicists will use SPIRIT to: discover how the conditions for habitability arise during planetary system formation; find and characterize exoplanets by measuring their sculpting effects on protoplanetary and debris disks; and study the formation, merger history, and star formation history of galaxies. 324.02
Designing the Balloon Experimental Twin Telescope for Infrared Interferometry Stephen Rinehart1, R. Barry2, D. Benford1, W. Danchi2, D. Fixsen3, C. Jhabvala4, D. Leisawitz5, L. Mundy6, R. Silverberg1, J. Staguhn7 1NASA's GSFC Code 665, 2NASA's GSFC Code 667, 3University of Maryland, College Park, 4NASA's GSFC Code 553, 5NASA's GSFC Code 605, 6University of Maryland College Park, 7Johns Hopkins University. 8:00 AM - 7:00 PM Essex Ballroom While infrared astronomy has revolutionized our understanding of galaxies, stars, and planets, further progress on major questions is stymied by the inescapable fact that the spatial resolution of single-aperture telescopes degrades at long wavelengths. The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter boom interferometer to operate in the FIR (30-90 μm) on a high altitude balloon. The long baseline will provide unprecedented angular resolution (~0.5[[Unsupported Character - ˝]]) in this band. In order for BETTII to be successful, the gondola must be designed carefully to provide a high level of stability with optics designed to send a collimated beam into the cryogenic instrument. We present results from the first 5 months of design effort for BETTII. Over this short period of time, we have made significant progress and are on track to complete the design of BETTII during this year. 324.03
How WISE Points to Future Far-Infrared Missions Dominic J. Benford1, D. T. Leisawitz1, E. L. Wright2 1NASA / GSFC, 2UCLA. 8:00 AM - 7:00 PM Essex Ballroom Based on the tantalizing science that is emerging from the first WISE discoveries, we consider the impact that the future will bring to far-infrared mission concepts. What we've learned from WISE gives us new investigations for missions like SPICA and SPIRIT. We highlight the new results from WISE and incorporate that into the context of the Far-Infrared Community Plan and the recent New Worlds, New Horizons documents. 324.04
8:00 AM - 7:00 PM Essex Ballroom In order to gain a comprehensive picture of galaxy evolution, we need to accurately measure the growing population of stars and super-massive black holes in dark matter halos. The processes that regulate this evolution are invariably those that are the most difficult to simulate, namely gas heating and cooling, star formation, black hole fueling and feedback from supernovae and AGN. Measurements of the PAH features, atomic fine-structure and H2 lines in the mid-infrared with Spitzer have been used successfully to probe the dust properties, power sources and state of the ISM in normal, starburst and AGN host galaxies at 0 < z < 3. At high redshifts, these lines enter the far-infrared, which is also home to critical diagnostics of the neutral and ionized ISM, such as [OI], [OIII], [NII], and [CII]. Recent results from Herschel, CSO, IRAM and APEX suggest that there is an extremely large range in far-infrared line fluxes and physical conditions among the most luminous, high-z galaxies. However, to measure the rest-frame far-infrared cooling lines in galaxies that dominate the far-infrared background, along with the full suite of mid-infrared atomic and molecular gas and dust features in ULIRGs over a wide range in redshift, a broadband spectrometer capable of reaching the natural astrophysical background over the 30-400 micron range is required. The Background Limited Infrared Sub-millimeter Spectrometer (BLISS) on the Japanese-led SPICA mission, would deliver unmatched sensitivity to evolving, dusty galaxies over all epochs. Here we discuss the scientific rationale behind BLISS and the opportunities afforded by US participation in the SPICA mission. 324.05
8:00 AM - 7:00 PM Essex Ballroom The far-IR waveband carries half of the photon energy ever produced in galaxies and quasars, evidence of the major role of dust-obscured star formation and black-hole growth had in bringing about the modern Universe. The bulk of this dust-obscured activity appears to have occurred in the first half of the Universe's history (z>1). We are developing the Background-Limited Infrared-Submillimeter Spectrograph (BLISS) to capitalize on SPICA's cold telescope and provide a breakthrough far-IR spectroscopy capability. BLISS-SPICA is 6 orders of magnitude faster than the spectrometers on Herschel and SOFIA in obtaining full-band spectra, and offer the capability to overcome the spatial confusion limit with spectroscopic capability. BLISS-SPICA will observe dust-obscured galaxies at all epochs back to the first billion years after the Big Bang (redshift 6), thereby probing the complete history of dust-obscured star formation and black-hole growth. It will also be extremely powerful for studying ice-giant planet formation in protoplanetary disks, with its sensitivity to very small amounts of gas. Given its enormous potential, BLISS has been recommended by Astro2010 as an example US contribution to SPICA. BLISS covers the 38-433 micron range in six grating-spectrometer bands, with two simultaneous sky positions. The baseline detector package is 4224 silicon-nitride micro-mesh leg-isolated bolometers with superconducting transition-edge-sensed (TES) thermistors, read out with a cryogenic time-domain multiplexer. All spectrometers and detector arrays are cooled to 50mK for optimal sensitivity. All technical elements of BLISS have heritage in mature scientific instruments, and many have flown. We present the science case for BLISS, as well as our progress in the key technical aspects: 1) detector and readout performance demonstration, 2) opto-mechanical instrument configuration, and 3) sub-K cooling and cryogenic system approach. 324.06
The Molecular Hydrogen Discovery Potential of SPICA/BLISS Philip N. Appleton1, L. Armus1, G. Helou1, C. M. Bradford2, E. Murphy1 1Caltech, 2JPL. 8:00 AM - 7:00 PM Essex Ballroom The BLISS spectrometer concept for the Space Infrared Telescope for Cosmology and Astrophysics (SPICA) observatory is an ideal instrument to search for powerful H2 line-emission at redshifts 2 < z < 5: the likely epoch at which massive galaxies are transformed from gas into stars. Unlike some other molecular tracers, the pure rotational transitions of molecular hydrogen at high redshift can only be studied in the far-IR, and direct measurements of H2 is out of reach of ALMA for redshifts less than z = 15. The IR H2 lines have proved to be surprisingly strong in low-redshift shock-driven systems, even in the presence of other metal cooling channels. However, little is yet know about the importance of shock-driven H2-line cooling at high-redshift in more pristine, metal-poor environments. We will show that the proposed SPICA/BLISS combination will provide a unique opportunity to probe into the sensitivity range expected for excited molecular hydrogen from galaxies up to at least z = 5. The study of the dissipation of kinetic energy through turbulence, strongly suspected as the main power-source in the local H2-bright systems, is likely to be of major importance in galaxy building. By analogy with these local H2-bright systems, SPICA/BLISS has the sensitivity to allow us to exploit this powerful shock-diagnostic for studying the most turbulent regions within forming galaxies. Download 2.63 Mb. Share with your friends:
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