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Your search keyword '"Gear, Walter"' showing total 10 results
Start Over Author "Gear, Walter" Publisher astronomical society of the pacific
10 results on '"Gear, Walter"'

1. Observing strategies for SCUBA

Author

Emerson, Darrel T., Payne, John M., Lightfoot, J., Duncan, W., Gear, Walter Keiran, Kelly, B., Smith, I., Emerson, Darrel T., Payne, John M., Lightfoot, J., Duncan, W., Gear, Walter Keiran, Kelly, B., and Smith, I.

3. SPIRE: The bolometer camera and spectrometer for FIRST

Author

Mangum, Jeffrey Gary, Radford, Simon John Elliott, Gear, Walter K., Griffin, Matthew Joseph, Mangum, Jeffrey Gary, Radford, Simon John Elliott, Gear, Walter K., and Griffin, Matthew Joseph

Abstract

We describe the scientific goals and outline design for the SPIRE instrument to be launched on the ESA cornerstone mission FIRST. SPIRE is a bolometer instrument covering the wavelength rage 200-600 microns, and will have three imaging channels centred at approximately 250, 350 and 500 microns, along with a broad-band imaging Fourier transform spectrometer operating from 200-670 microns. The photometer will observe the same 4 x 8 arcminute field of view simultaneously in all three bands with diffraction-limited angular resolution (18 arcseconds at 250 microns). The spectrometer will have a field of view of 2.6 × 2.6 arcminutes and will have spectral resolution adjustable from approximately 20 to 1000. The detector arrays will operate at helium-3 temperature (0.3 K). The primary science goals of SPIRE are deep extragalactic and galactic surveys for high-redshift galaxies and young protostellar sources respectively, and follow-up spectrophotometric observations.

4. Polarimetric observations of 15 AGNs at high frequencies

Author

Romney, J. D., Reid, M. J., Jorstad, S., Marscher, A., Stevens, J., Robson, I., Lister, M., Stirling, A., Cawthorne, T., Smith, P., Gomez, J. L., Gear, Walter Kieran, Romney, J. D., Reid, M. J., Jorstad, S., Marscher, A., Stevens, J., Robson, I., Lister, M., Stirling, A., Cawthorne, T., Smith, P., Gomez, J. L., and Gear, Walter Kieran

Abstract

We have obtained total and polarized intensity images of 15 AGNs with the VLBA at 7 mm at 17 epochs from 25/26 March 1998 to 14 April 2001. The VLBA observations are accompanied at many epochs by simultaneous measurements of polarization at 1.35/0.85 mm as well as less frequent simultaneous optical polarization measurements. We discuss the similarities and complexities of polarization behavior at different frequencies along with the VLBI properties.

5. Submillimetre polarimetry of blazars

Author

Roberge, W. G., Whittet, D. C. B., Nartallo, R., Gear, Walter Kieran, Murray, A. G., Hobson, E. I., Hough, J. H., Roberge, W. G., Whittet, D. C. B., Nartallo, R., Gear, Walter Kieran, Murray, A. G., Hobson, E. I., and Hough, J. H.

Abstract

We report on preliminary results from the first monitoring campaign of the submillimetre polarization of a sample of Blazars. The observations have been carried out with the James Clerk Maxwell Telescope between 1991 and 1994.

6. Deep sub-millimeter surveys: highly luminous far-infrared sources at high redshift

Author

Bunker, A. J., Van Breugel, W. J. M., Webb, T, Lilly, S., Eales, Stephen Anthony, Gear, Walter Kieran, Dune, L., Clements, D., Bond, D., Crampton, D., Hammer, F., Le Fevre, O., Bunker, A. J., Van Breugel, W. J. M., Webb, T, Lilly, S., Eales, Stephen Anthony, Gear, Walter Kieran, Dune, L., Clements, D., Bond, D., Crampton, D., Hammer, F., and Le Fevre, O.

7. Polarization calibration of the QUaD experiment

Author

Hinderks, J., Ade, Peter A. R., Bock, J., Bowden, M., Brown, M. L., Cahill, G., Carlstrom, J. E., Castro, P. G., Church, S., Culverhouse, T., Friedman, R., Ganga, K., Gear, Walter Kieran, Gupta, S., Harris, J., Haynes, V., Kovac, J., Lange, A. E., Leitch, E., Mallie, O. E., Melhuish, S., Memari, Y., Murphy, A., Orlando, A., Schwarz, R., Sullivan, C. O., Piccirillo, L., Pryke, C., Rajguru, N., Rusholme, B., Taylor, A. N., Thompson, K. L., Tucker, Carole Elizabeth, Turner, A. H., Wu, E., Zemcov, M., Hinderks, J., Ade, Peter A. R., Bock, J., Bowden, M., Brown, M. L., Cahill, G., Carlstrom, J. E., Castro, P. G., Church, S., Culverhouse, T., Friedman, R., Ganga, K., Gear, Walter Kieran, Gupta, S., Harris, J., Haynes, V., Kovac, J., Lange, A. E., Leitch, E., Mallie, O. E., Melhuish, S., Memari, Y., Murphy, A., Orlando, A., Schwarz, R., Sullivan, C. O., Piccirillo, L., Pryke, C., Rajguru, N., Rusholme, B., Taylor, A. N., Thompson, K. L., Tucker, Carole Elizabeth, Turner, A. H., Wu, E., and Zemcov, M.

Abstract

We describe the polarization calibration of the QUaD experiment, including determination of the polarization efficiency of the detectors and their orientation angles. QUaD is a millimeter-wavelength polarimeter that observed the Cosmic Microwave Background (CMB) from a site at the South Pole. The experiment comprises a 2.64 m Cassegrain telescope equipped with a cryogenically cooled receiver containing an array of 62 polarization-sensitive bolometers. The focal plane contains pixels at two different frequency bands, 100 GHz and 150 GHz, with angular resolutions of 5prime and 3farcm5, respectively. The high angular resolution allows observation of CMB temperature and polarization anisotropies over a wide range of scales. The instrument commenced operation in early 2005 and collected science data during three successive Austral winter seasons of observation.

8. Results from the Herschel Key Program MESS

Author

Groenewegen, M. A. T., Waelkens, C., Barlow, M. J., Kerschbaum, F., Garcia-Lario, P., Cernicharo, J., Blommaert, J. A. D. L., Bouwman, J., Cohen, M., Cox, N., Decin, L., Exter, K., Gear, Walter Kieran, Gomez, Haley Louise, Hargrave, Peter Charles, Henning, Th., Hutsemekers, D., Ivison, R. J., Jorissen, A., Krause, O., Ladjal, D., Leeks, S. J., Lim, T. L., Matsuura, Mikako, Naze, Y., Olofsson, G., Ottensamer, R., Polehampton, E., Posch, T., Rauw, G., Royer, P., Sibthorpe, B., Swinyard, B. M., Ueta, T., Vamvatira- Nakou, C., Vandenbussche, B., Van de Steene, G. C., Van Eck, S., Van Hoof, P. A. M., Van Winckel, H., Verdugo, E., Wesson, R., Groenewegen, M. A. T., Waelkens, C., Barlow, M. J., Kerschbaum, F., Garcia-Lario, P., Cernicharo, J., Blommaert, J. A. D. L., Bouwman, J., Cohen, M., Cox, N., Decin, L., Exter, K., Gear, Walter Kieran, Gomez, Haley Louise, Hargrave, Peter Charles, Henning, Th., Hutsemekers, D., Ivison, R. J., Jorissen, A., Krause, O., Ladjal, D., Leeks, S. J., Lim, T. L., Matsuura, Mikako, Naze, Y., Olofsson, G., Ottensamer, R., Polehampton, E., Posch, T., Rauw, G., Royer, P., Sibthorpe, B., Swinyard, B. M., Ueta, T., Vamvatira- Nakou, C., Vandenbussche, B., Van de Steene, G. C., Van Eck, S., Van Hoof, P. A. M., Van Winckel, H., Verdugo, E., and Wesson, R.

Abstract

MESS (Mass loss of Evolved StarS) is a Herschel Guaranteed Time Key Program that will image about 100, and do spectroscopy of about 50, post-main-sequence objects of all flavours: AGB stars, post-AGB stars, planetary nebulae, luminous blue variables, Wolf-Rayet stars, and supernova remnants. In this review the implementation and current status of MESS is outlined, and first results are presented.

9. Herschel PACS and SPIRE Imaging of CW Leonis

Author

Kerschbaum, F., Lebzelter, T., Wing, R. F., Klotz, D., Ladjal, D., Barlow, M., Groenewegen, M., Ueta, T., Blommaert, J. A. D. L., Cohen, M., Decin, L., De Meester, W., Exter, K., Gear, Walter Kieran, Gomez, Haley Louise, Hargrave, Peter Charles, Hugyen, R., Ivison, R. J., Jean, C., Leeks, S. J., Lim, T. L., Olofsson, G., Polehampton, E., Posch, T., Regibo, S., Royer, P., Sibthorpe, B., Swinyard, B. M., Vandenbussche, B., Waelkens, C., Wesson, R., Kerschbaum, F., Lebzelter, T., Wing, R. F., Klotz, D., Ladjal, D., Barlow, M., Groenewegen, M., Ueta, T., Blommaert, J. A. D. L., Cohen, M., Decin, L., De Meester, W., Exter, K., Gear, Walter Kieran, Gomez, Haley Louise, Hargrave, Peter Charles, Hugyen, R., Ivison, R. J., Jean, C., Leeks, S. J., Lim, T. L., Olofsson, G., Polehampton, E., Posch, T., Regibo, S., Royer, P., Sibthorpe, B., Swinyard, B. M., Vandenbussche, B., Waelkens, C., and Wesson, R.

Abstract

Far-IR (FIR) images of the archetype carbon star CW Leo (IRC +10216) by the Herschel Space Observatory (Pilbratt et al. 2010) reveal an extended structure at about 11′ from the star which correlates with the UV structure seen by the GALaxy Evolution EXplorer Space Observatory (GALEX) (Sahai & Chronopoulos 2010). The UV emission is believed to be due to the shocked asymptotic giant branch (AGB) wind with the interstellar medium (ISM) (Sahai & Chronopoulos). We present our main results from the Herschel data on the wind–ISM interaction.

10. Multi-frequency polarization properties of Blazars

Author

Adamson, Andy, Aspin, Colin, Davis, Chris J., Fujiyoshi, Takuya, Jorstad, S. G., Marscher, A. P., Stevens, J. A., Robson, E. I., Lister, J. L., Stirling, A. M., Smith, P. S., Cawthorne, T. V., Gomez, J. L., Gabuzda, D. C., Gear, Walter Kieran, Adamson, Andy, Aspin, Colin, Davis, Chris J., Fujiyoshi, Takuya, Jorstad, S. G., Marscher, A. P., Stevens, J. A., Robson, E. I., Lister, J. L., Stirling, A. M., Smith, P. S., Cawthorne, T. V., Gomez, J. L., Gabuzda, D. C., and Gear, Walter Kieran

Abstract

We have obtained total and polarized intensity images of 15 AGNs with the VLBA at 7 mm at 17 epochs, accompanied at many epochs by nearly simultaneous measurements of polarization at 1.35/0.85 mm and at optical wavelengths. Analysis of the data shows an obvious connection between the polarized emission at high frequencies and the most strongly polarized features in parsec-scale jets. The largest deviations between polarization parameters at different frequencies are detected when a new compact knot emerges from the core, and are likely caused by very short time-scale (<1 week) polarization variability during the events.

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