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8 results on '"Samoska, L.A."'

2. Detection of OH+ and H2O+ towards Orion KL

Author

Gupta, H., Rimmer, P., Pearson, J.C., Yu, S., Herbst, E., Harada, N., Bergin, E.A., Neufeld, D.A., Melnick, G.J., Bachiller, R., Bells, T.A., Blake, G.A., Caux, E., Ceccarelli, C., Cernicharo, J., Chattopadhyay, G., Comito, C., Cabrit, S., Crockett, N.R., Daniel, F., Falgarone, E., Diez-Gonzalez, M.C., Dubernet, M.-L., Erickson, N., Emprechtinger, M., Encrenaz, P., Gerin, M., Gill, J.J., Giesen, T.F., Goicoechea, J.R., Goldsmith, P.F., Joblin, C., Johnstone, D., Langer, W.D., Larsson, B., Latter, W.B., Lin, R.J., Lis, D.C., Liseau, R., Lord, S.D., Maiwald, F.W., Maret, S., Martin, P.G., Martin-Pintado, J., Menten, K.M., Morris, P., Muller, H.S.P., Murphy, J.A., Nordh, L.H., Olberg, M., Ossenkopf, V., Pagani, L., Perault, M., Phillips , T.G., Plume, R., Qin, S.-L., Salez, M., Samoska, L.A., Schilke, P., Schlecht, E., Schlemmer, S., Szczerba, R., Stutzki, J., Trappe, N., van der Tak, F.F.S., Vastel, C., Wang, S., Yorke, H.W., Zmuidzinas, J., Boogert, A., Gusten, R., Hartogh, P., Honigh, N., Karpov, A., Kooi, J., Krieg, J.-M., Schieder, R., and Zaal, P.

Subjects
Experimental Physics
Abstract

We report observations of the reactive molecular ions OH+, H2O+, and H3O+ towards Orion KL with Herschel/HIFI. All three N = 1−0 finestructure transitions of OH+ at 909, 971, and 1033 GHz and both fine-structure components of the doublet ortho-H2O+ 111−000 transition at 1115 and 1139 GHz were detected; an upper limit was obtained for H3O+. OH+ and H2O+ are observed purely in absorption, showing a narrow component at the source velocity of 9 km s−1, and a broad blueshifted absorption similar to that reported recently for HF and para-H18 2 O, and attributed to the low velocity outflow of Orion KL.We estimate column densities of OH+ and H2O+ for the 9 kms−1 component of 9±3×1012 cm−2 and 7±2×1012 cm−2, and those in the outflow of 1.9±0.7×1013 cm−2 and 1.0±0.3×1013 cm−2. Upper limits of 2.4×1012 cm−2 and 8.7×1012 cm−2 were derived for the column densities of ortho and para-H3O+ from transitions near 985 and 1657 GHz. The column densities of the three ions are up to an order of magnitude lower than those obtained from recent observations ofW31C and W49N. The comparatively low column densities may be explained by a higher gas density despite the assumption of a very high ionization rate.

Published
2010

3. The Herschel-Heterodyne Instrument for the Far-Infrared (HIFI)

Author

Graauw, T. de, Helmich, F.P., Phillips, T.G., Stutzki, J., Caux, E., Whyborn, N.D., Dieleman, P., Roelfsema, P.R., Aarts, H., Assendorp, R., Bachiller, R., Baechtold, W., Barcia, A., Beintema, D.A., Belitsky, V., Benz, A.O., Bieber, R., Boogert, A., Borys, C., Bumble, B., Caïs, P., Caris, M., Cerulli-Irelli, P., Chattopadhyay, G., Cherednichenko, S., Ciechanowicz, M., Coeur-Joly, O., Comito, C., Cros, A., Jonge, A. de, Lange, G. de, Delforges, B., Delorme, Y., Boggende, T. den, Desbat, J.M., Diez-González, C., Di Giorgio, A.M., Dubbeldam, L., Edwards, K., Eggens, M., Erickson, N., Evers, J., Fich, M., Finn, T., Franke, B., Gaier, T., Gal, C., Gao, J.R., Gallego, J.D., Gauffre, S., Gill, J.J., Glenz, S., Golstein, H., Goulooze, H., Gunsing, T., Güsten, R., Hartogh, P., Hatch, W.A., Higgins, R., Honingh, E.C., Huisman, R., Jackson, B.D., Jacobs, H., Jacobs, K., Jarchow, C., Javadi, H., Jellema, W., Justen, M., Karpov, A., Kasemann, C., Kawamura, J., Keizer, G., Kester, D., Klapwijk, T.M., Klein, T., Kollberg, E., Kooi, J., Kooiman, P.P., Kopf, B., Krause, M., Krieg, J.M., Kramer, C., Kruizenga, B., Kuhn, T., Laauwen, W., Lai, R., Larsson, B., Leduc, H.G., Leinz, C., Lin, R.H., Liseau, R., Liu, G.S., Loose, A., López-Fernandez, I., Lord, S., Luinge, W., Marston, A., Martín-Pintado, J., Maestrini, A., Maiwald, F.W., McCoey, C., Mehdi, I., Megej, A., Melchior, M., Meinsma, L., Merkel, H., Michalska, M., Monstein, C., Moratschke, D., Morris, P., Muller, H., Murphy, J.A., Naber, A., Natale, E., Nowosielski, W., Nuzzolo, F., Olberg, M., Olbrich, M., Orfei, R., Orleanski, P., Ossenkopf, V., Peacock, T., Pearson, J.C., Peron, I., Phillip-May, S., Piazzo, L., Planesas, P., Rataj, M., Ravera, L., Risacher, C., Salez, M., Samoska, L.A., Saraceno, P., Schieder, R., Schlecht, E., Schlöder, F., Schmülling, F., Schultz, M., Schuster, K., Siebertz, O., Smit, H., Szczerba, R., Shipman, R., Steinmetz, E., Stern, J.A., Stokroos, M., Teipen, R., Teyssier, D., Tils, T., Trappe, N., Baaren, C. van, Leeuwen, B.J. van, Stadt, H. van de, Visser, H., Wildeman, K.J., Wafelbakker, C.K., Ward, J.S., Wesselius, P., Wild, W., Wulff, S., Wunsch, H.J., Tielens, X., Zaal, P., Zirath, H., Zmuidzinas, J., Zwart, F., Graauw, T. de, Helmich, F.P., Phillips, T.G., Stutzki, J., Caux, E., Whyborn, N.D., Dieleman, P., Roelfsema, P.R., Aarts, H., Assendorp, R., Bachiller, R., Baechtold, W., Barcia, A., Beintema, D.A., Belitsky, V., Benz, A.O., Bieber, R., Boogert, A., Borys, C., Bumble, B., Caïs, P., Caris, M., Cerulli-Irelli, P., Chattopadhyay, G., Cherednichenko, S., Ciechanowicz, M., Coeur-Joly, O., Comito, C., Cros, A., Jonge, A. de, Lange, G. de, Delforges, B., Delorme, Y., Boggende, T. den, Desbat, J.M., Diez-González, C., Di Giorgio, A.M., Dubbeldam, L., Edwards, K., Eggens, M., Erickson, N., Evers, J., Fich, M., Finn, T., Franke, B., Gaier, T., Gal, C., Gao, J.R., Gallego, J.D., Gauffre, S., Gill, J.J., Glenz, S., Golstein, H., Goulooze, H., Gunsing, T., Güsten, R., Hartogh, P., Hatch, W.A., Higgins, R., Honingh, E.C., Huisman, R., Jackson, B.D., Jacobs, H., Jacobs, K., Jarchow, C., Javadi, H., Jellema, W., Justen, M., Karpov, A., Kasemann, C., Kawamura, J., Keizer, G., Kester, D., Klapwijk, T.M., Klein, T., Kollberg, E., Kooi, J., Kooiman, P.P., Kopf, B., Krause, M., Krieg, J.M., Kramer, C., Kruizenga, B., Kuhn, T., Laauwen, W., Lai, R., Larsson, B., Leduc, H.G., Leinz, C., Lin, R.H., Liseau, R., Liu, G.S., Loose, A., López-Fernandez, I., Lord, S., Luinge, W., Marston, A., Martín-Pintado, J., Maestrini, A., Maiwald, F.W., McCoey, C., Mehdi, I., Megej, A., Melchior, M., Meinsma, L., Merkel, H., Michalska, M., Monstein, C., Moratschke, D., Morris, P., Muller, H., Murphy, J.A., Naber, A., Natale, E., Nowosielski, W., Nuzzolo, F., Olberg, M., Olbrich, M., Orfei, R., Orleanski, P., Ossenkopf, V., Peacock, T., Pearson, J.C., Peron, I., Phillip-May, S., Piazzo, L., Planesas, P., Rataj, M., Ravera, L., Risacher, C., Salez, M., Samoska, L.A., Saraceno, P., Schieder, R., Schlecht, E., Schlöder, F., Schmülling, F., Schultz, M., Schuster, K., Siebertz, O., Smit, H., Szczerba, R., Shipman, R., Steinmetz, E., Stern, J.A., Stokroos, M., Teipen, R., Teyssier, D., Tils, T., Trappe, N., Baaren, C. van, Leeuwen, B.J. van, Stadt, H. van de, Visser, H., Wildeman, K.J., Wafelbakker, C.K., Ward, J.S., Wesselius, P., Wild, W., Wulff, S., Wunsch, H.J., Tielens, X., Zaal, P., Zirath, H., Zmuidzinas, J., and Zwart, F.

Abstract

Aims. This paper describes the Heterodyne Instrument for the Far-Infrared (HIFI) that was launched onboard ESA's Herschel Space Observatory in May 2009. Methods. The instrument is a set of 7 heterodyne receivers that are electronically tuneable, covering 480-1250 GHz with SIS mixers and the 1410-1910 GHz range with hot electron bolometer (HEB) mixers. The local oscillator (LO) subsystem comprises a Ka-band synthesizer followed by 14 chains of frequency multipliers and 2 chains for each frequency band. A pair of auto-correlators and a pair of acousto-optical spectrometers process the two IF signals from the dual-polarization, single-pixel front-ends to provide instantaneous frequency coverage of 2 × 4 GHz, with a set of resolutions (125 kHz to 1 MHz) that are better than 0.1 km s-1. Results. After a successful qualification and a pre-launch TB/TV test program, the flight instrument is now in-orbit and completed successfully the commissioning and performance verification phase. The in-orbit performance of the receivers matches the pre-launch sensitivities. We also report on the in-orbit performance of the receivers and some first results of HIFI's operations.

Published
2010

4. Herschel observations of deuterated water towards Sgr B2(M)

Author

Comito, C., Schilke, P., Rolffs, R., Lis, D.C., Belloche, A., Bergin, E.A., Phillips , T.G., Bell, T.A., Crockett, N.R., Wang, S., Blake, G.A., Caux, E., Ceccarelli, C., Cernicharo, J., Daniel, F., Dubernet, M.-L., Emprechtinger, M., Encrenaz, P., Gerin, M., Giesen, T.F., Goicoechea, J.R., Goldsmith, P.F., Gupta, H., Herbst, E., Joblin, C., Johnstone, D., Langer, W.D., Latter, W.D., Lord, S.D., Maret, S., Martin, P.G., Melnick, G.J., Menten, K.M., Morris, P., Muller, H.S.P., Murphy, J.Anthony, Neufeld, D.A., Ossenkopf, V., Pearson, J.C., Perault, M., Plume, R., Qin, S.-L., Schlemmer, S., Stutzki, J., Trappe, Neil, van der Tak, F.F.S., Vastel, C., Yorke, H.W., Yu, S., Olberg, M., Szczerba, R., Larsson, B., Liseau, R., Lin, R.H., Samoska, L.A., Schlecht, E., Comito, C., Schilke, P., Rolffs, R., Lis, D.C., Belloche, A., Bergin, E.A., Phillips , T.G., Bell, T.A., Crockett, N.R., Wang, S., Blake, G.A., Caux, E., Ceccarelli, C., Cernicharo, J., Daniel, F., Dubernet, M.-L., Emprechtinger, M., Encrenaz, P., Gerin, M., Giesen, T.F., Goicoechea, J.R., Goldsmith, P.F., Gupta, H., Herbst, E., Joblin, C., Johnstone, D., Langer, W.D., Latter, W.D., Lord, S.D., Maret, S., Martin, P.G., Melnick, G.J., Menten, K.M., Morris, P., Muller, H.S.P., Murphy, J.Anthony, Neufeld, D.A., Ossenkopf, V., Pearson, J.C., Perault, M., Plume, R., Qin, S.-L., Schlemmer, S., Stutzki, J., Trappe, Neil, van der Tak, F.F.S., Vastel, C., Yorke, H.W., Yu, S., Olberg, M., Szczerba, R., Larsson, B., Liseau, R., Lin, R.H., Samoska, L.A., and Schlecht, E.

Abstract

Observations of HDO are an important complement for studies of water, because they give strong constraints on the formation processes – grain surfaces versus energetic process in the gas phase, e.g. in shocks. The HIFI observations of multiple transitions of HDO in Sgr B2(M) presented here allow the determination of the HDO abundance throughout the envelope, which has not been possible before with ground-based observations only. The abundance structure has been modeled with the spherical Monte Carlo radiative transfer code RATRAN, which also takes radiative pumping by continuum emission from dust into account. The modeling reveals that the abundance of HDO rises steeply with temperature from a low abundance (2.5 × 10−11) in the outer envelope at temperatures below 100 K through a medium abundance (1.5 × 10−9) in the inner envelope/outer core at temperatures between 100 and 200 K, and finally a high abundance ( 3.5 × 10−9) at temperatures above 200 K in the hot core.

Published
2010

5. The Herschel-Heterodyne Instrument for the Far-Infrared (HIFI)

Author

de Graauw, Th., Helmich, F.P., Phillips , T.G., Stutzki, J., Caux, E., Whyborn, N.D., Dieleman, P., Roelfsema, P.R., Aarts, H., Assendorp, R., Bachiller, R., Baechtold, W., Barcia, A., Beintema, D.A., Belitsky, V., Benz, A.O., Bieber, R., Boogert, A., Borys, C., Bumble, B., Cais, P., Caris, M., Cerulli-Irelli, P., Chattopadhyay, G., Cherednichenko, S., Ciechanowicz, M., Coeur-Joly, O., Comito, C., Cros, A., de Jonge, A., de Lange, G., Delforges, B., Delorme, Y., den Boggende, T., Desbat, J.-M., Diez-Gonzalez, C., Di Giorgio, A.M., Dubbeldam, L., Edwards, K., Eggens, M., Erickson, N., Evers, J., Fich, M., Finn, T., Franke, B., Gaier, T., Gal, C., Gao, J.R., Gallego, J.-D., Gauffre, S., Gill, J.J., Glenz, S., Golstein, H., Goulooze, H., Gunsing, T., Gusten, R., Hartogh, P., Hatch, W.A., Higgins, R., Honingh, E.C., Huisman, R., Jackson, B.D., Jacobs, H., Jacobs, K., Jarchow, C., Javadi, H., Jellema, W., Justen, M., Karpov, A., Kasemann, C., Kawamura, J., Keizer, G., Kester, D., Klapwijk, T.M., Klein, Th., Kollberg, E., Kooi, J., Kooiman, P.-P., Kopf, B., Krause, M., Krieg, J.-M., Kramer, C., Kruizenga, B., Kuhn, T., Laauwen, W., Lai, R., Larsson, B., Leduc, H.G., Leinz, C., Lin, R.H., Liseau, R., Liu, G.S., Loose, A., Lopez-Fernandez, I., Lord, S., Luinge, W., Marston, A., Martin-Pintado, J., Maestrini, A., Maiwald, F.W., McCoey, C., Mehdi, I., Megej, A., Melchior, M., Meinsma, L., Merkel, H., Michalska, M., Monstein, C., Moratschke, D., Morris, P., Muller, H., Murphy, J.Anthony, Naber, A., Natale, E., Nowosielski, W., Nuzzolo, F., Olberg, M., Olbrich, M., Orfei, R., Orleanski, P., Ossenkopf, V., Peacock, T., Pearson, J.C., Peron, I., Phillip-May, S., Piazzo, L., Planesas, P., Rataj, M., Ravera, L., Risacher, C., Salez, M., Samoska, L.A., Saraceno, P., Schieder, R., Schlecht, E., Schloder, F., Schmulling, F., Schultz, M., Schuster, K., Siebertz, O., Smit, H., Szczerba, R., Shipman, R., Steinmetz, E., Stern, J.A., Stokroos, M., Teipen, R., Teyssier, D., Tils, T., Trappe, Neil, van Baaren, C., van Leeuwen, B.-J., van de Stadt, H., Visser, H., Wildeman, K.J., Wafelbakker, C.K., Ward, J.S., Wesselius, P., Wild, W., Wulff, S., Wunsch, H.-J., Tielens, X., Zaal, P., Zirath, H., Zmuidzinas, J., Zwart, F., de Graauw, Th., Helmich, F.P., Phillips , T.G., Stutzki, J., Caux, E., Whyborn, N.D., Dieleman, P., Roelfsema, P.R., Aarts, H., Assendorp, R., Bachiller, R., Baechtold, W., Barcia, A., Beintema, D.A., Belitsky, V., Benz, A.O., Bieber, R., Boogert, A., Borys, C., Bumble, B., Cais, P., Caris, M., Cerulli-Irelli, P., Chattopadhyay, G., Cherednichenko, S., Ciechanowicz, M., Coeur-Joly, O., Comito, C., Cros, A., de Jonge, A., de Lange, G., Delforges, B., Delorme, Y., den Boggende, T., Desbat, J.-M., Diez-Gonzalez, C., Di Giorgio, A.M., Dubbeldam, L., Edwards, K., Eggens, M., Erickson, N., Evers, J., Fich, M., Finn, T., Franke, B., Gaier, T., Gal, C., Gao, J.R., Gallego, J.-D., Gauffre, S., Gill, J.J., Glenz, S., Golstein, H., Goulooze, H., Gunsing, T., Gusten, R., Hartogh, P., Hatch, W.A., Higgins, R., Honingh, E.C., Huisman, R., Jackson, B.D., Jacobs, H., Jacobs, K., Jarchow, C., Javadi, H., Jellema, W., Justen, M., Karpov, A., Kasemann, C., Kawamura, J., Keizer, G., Kester, D., Klapwijk, T.M., Klein, Th., Kollberg, E., Kooi, J., Kooiman, P.-P., Kopf, B., Krause, M., Krieg, J.-M., Kramer, C., Kruizenga, B., Kuhn, T., Laauwen, W., Lai, R., Larsson, B., Leduc, H.G., Leinz, C., Lin, R.H., Liseau, R., Liu, G.S., Loose, A., Lopez-Fernandez, I., Lord, S., Luinge, W., Marston, A., Martin-Pintado, J., Maestrini, A., Maiwald, F.W., McCoey, C., Mehdi, I., Megej, A., Melchior, M., Meinsma, L., Merkel, H., Michalska, M., Monstein, C., Moratschke, D., Morris, P., Muller, H., Murphy, J.Anthony, Naber, A., Natale, E., Nowosielski, W., Nuzzolo, F., Olberg, M., Olbrich, M., Orfei, R., Orleanski, P., Ossenkopf, V., Peacock, T., Pearson, J.C., Peron, I., Phillip-May, S., Piazzo, L., Planesas, P., Rataj, M., Ravera, L., Risacher, C., Salez, M., Samoska, L.A., Saraceno, P., Schieder, R., Schlecht, E., Schloder, F., Schmulling, F., Schultz, M., Schuster, K., Siebertz, O., Smit, H., Szczerba, R., Shipman, R., Steinmetz, E., Stern, J.A., Stokroos, M., Teipen, R., Teyssier, D., Tils, T., Trappe, Neil, van Baaren, C., van Leeuwen, B.-J., van de Stadt, H., Visser, H., Wildeman, K.J., Wafelbakker, C.K., Ward, J.S., Wesselius, P., Wild, W., Wulff, S., Wunsch, H.-J., Tielens, X., Zaal, P., Zirath, H., Zmuidzinas, J., and Zwart, F.

Abstract

Aims. This paper describes the Heterodyne Instrument for the Far-Infrared (HIFI) that was launched onboard ESA’s Herschel Space Observatory in May 2009. Methods. The instrument is a set of 7 heterodyne receivers that are electronically tuneable, covering 480−1250 GHz with SIS mixers and the 1410−1910 GHz range with hot electron bolometer (HEB) mixers. The local oscillator (LO) subsystem comprises a Ka-band synthesizer followed by 14 chains of frequency multipliers and 2 chains for each frequency band. A pair of auto-correlators and a pair of acousto-optical spectrometers process the two IF signals from the dual-polarization, single-pixel front-ends to provide instantaneous frequency coverage of 2 × 4 GHz, with a set of resolutions (125 kHz to 1 MHz) that are better than 0.1 kms−1. Results. After a successful qualification and a pre-launch TB/TV test program, the flight instrument is now in-orbit and completed successfully the commissioning and performance verification phase. The in-orbit performance of the receivers matches the pre-launch sensitivities. We also report on the in-orbit performance of the receivers and some first results of HIFI’s operations.

Published
2010

7. Strong far-infrared intersubband absorption under normal incidence in heavily n-type doped....

Author

Samoska, L.A., Brar, Berinder, and Kroemer, H.

Subjects
*ABSORPTION, *SUPERLATTICES, *SEMICONDUCTOR doping
Abstract

Examines the long-wavelength intersubband absorption under normal incidence in heavily doped binary-binary GaSb-AlSb superlattices. Observation of peak absorption per quantum well; Creation of intersubband transition under normal incident radiation; Presence of small energy difference in ellipsoidal L valleys in GaSb.

Published
1993
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8. Far-infrared photoresponse of the InAs/GaInSb superlattice.

Author

Campbell, I.H., Sela, I., Laurich, B.K., Smith, D.L., Bolognesi, C.R., Samoska, L.A., Gossard, A.C., and Kroemer, H.

Subjects
SUPERLATTICES, PHOTOLUMINESCENCE, SUPERCONDUCTORS
Abstract

Examines the far-infrared photoresponse of indium arsenide (InAs)/gallium indium antimonide (GaInSb) superlattices on gallium antimonide (GaSb) substrates. Determination of the superlattice structure; Measurement of the infrared transmission; Recovery time of the photoconductive response.

Published
1991
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