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251. LOTIS, Super-LOTIS, Sloan Digital Sky Survey, and Tautenburg Observations of GRB 010921

Author

Park, H. S., primary, Williams, G. G., additional, Hartmann, D. H., additional, Lamb, D. Q., additional, Lee, B. C., additional, Tucker, D. L., additional, Klose, S., additional, Stecklum, B., additional, Henden, A., additional, Adelman, J., additional, Barthelmy, S. D., additional, Briggs, J. W., additional, Brinkmann, J., additional, Chen, B., additional, Cline, T., additional, Csabai, I., additional, Gehrels, N., additional, Harvanek, M., additional, Hennessy, G. S., additional, Hurley, K., additional, Ivezić, Željko, additional, Kent, S., additional, Kleinman, S. J., additional, Krzesinski, J., additional, Lindsay, K., additional, Long, D., additional, Nemiroff, R., additional, Neilsen, E. H., additional, Nitta, A., additional, Newberg, H. J., additional, Newman, P. R., additional, Perez, D., additional, Periera, W., additional, Schneider, D. P., additional, Snedden, S. A., additional, Stoughton, C., additional, Vanden Berk, D. E., additional, York, D., additional, and Ziock, K., additional

Published
2002
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254. The Polarization Evolution of the Optical Afterglow of GRB 030329.

Author

Greiner, J., Klose, S., Reinsch, K., Schmid, H. M., Sari, R., Hartmann, D. H., Kouveliotou, C., Rau, A., Palazzi, E., Straubmeier, C., Stecklum, B., Zharikov, S., Tovmassian, G., Bärnbantner, O., Ries, C., Jehin, E., Henden, A., Kaas, A. A., Grav, T., and Hjorth, J.

Subjects
AFTERGLOW (Physics), OPTICAL polarization, GAMMA ray bursts, MAGNETIC fields, ASTROPHYSICS, ASTRONOMY
Abstract

We report 31 polarimetric observations of the afterglow of GRB 030329 with high signal-to-noise and high sampling frequency. The data imply that the afterglow magnetic field has small coherence length and is mostly random, probably generated by turbulence. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2004
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255. GRB 030329 with SARA and TLS.

Author

Lindsay, K., Zeh, A., Hartmann, D. H., Klose, S., Shaw, S., Leake, M., Webb, J., Stecklum, B., Williams, M., and Howard, E.

Subjects
GAMMA ray bursts, NUCLEAR reactions, PHOTOMETRY, SUPERNOVAE, ASTRONOMY, ASTROPHYSICS
Abstract

We present B band observations performed with the SARA 0.9m telescope at KPNO and the Tautenburg 1.34m Schmidt telescope in Tautenburg, Germany, for the optical afterglow of the gamma-ray burst GRB 030329. Observations were carried out from March 30.12 to April 8.29 (UT) with SARA, and from March 30.80 to April 7.00 (UT) with the Tautenburg Schmidt. This burst provides the best covered GRB afterglow light curve to date. The afterglow exhibits a complicated “fine structure” with several episodes of significant re-brightening. These episodes inevitably demand a more detailed numerical fit which introduces a larger number of free parameters. It is difficult to separate the light from the re-brightening phases and the light from the underlying supernova. The photometric data show an average temporal regression in the flux of the optical afterglow, that is typical for GRB afterglow. However, “bumps and wiggles” clearly suggest a degree of complexity resulting from the re-brightening phases that is not easily fitted with standard models. At late time the light curve receives a significant contribution from an underlying supernova component (SN 2002dh). We argue that in cases such as GRB 030329 single site observations are inadequate to properly sample the evolving flux. Consequently, simple broken power law fits of data obtained with just one telescope may lead to rather poor descriptions of the afterglow charcateristics. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2004
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256. The Disk, Jet, and Environment of the Nearest Herbig Ae Star: HD 104237.

Author

Grady, C.A., Woodgate, B., Torres, Carlos A.O., Henning, Th., Apai, D., Rodmann, J., Hongchi Wang, Stecklum, B., Linz, H., Williger, G.M., Brown, A., Wilkinson, E., Harper, G.M., and Herczeg, G.J.

Subjects
HERBIG Ae/Be stars, STELLAR spectra, DISKS (Astrophysics), COSMIC dust, ASTROPHYSICAL jets, ASTROPHYSICS
Abstract

The environment of the nearest Herbig Ae star has been investigated through a program of multi-wavelength, high contrast and high spatial resolution imagery, FUV through optical integrated light spectroscopy, and FUV spatially resolved spectroscopy. HD 104237 is the primary of a 5 Myr old aggregate of at least 4 PMS stars, 2 of which in addition to HD 104237 have IR excesses indicating the presence of dust disks. HD 104237 is actively accreting, and is driving a bipolar outflow (HH 669) which can be traced 2.65″ from the star and which is viewed at an inclination of18-11+14°. The counterjet can be traced no closer than 0.6″ (79 AU) from the star, providing a firm upper limit to the size of the disk. The absence of spatially extended H2 emission, FUV reflection nebulosity, and mid-IR PAH emission features are all consistent with dust settling and the presence of a geometrically shadowed disk. The combination of proximity, low reddening, and the high density of disks in the HD 104237 association make this group of stars an ideal laboratory for probing the comparative evolution of planetary systems. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2004
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257. Detection of an optical filament in the Monogem Ring

Author

Weinberger, R., Temporin, S., Stecklum, B., Weinberger, R., Temporin, S., and Stecklum, B.

Abstract

The Monogem Ring is a huge bright soft X-ray enhancement with a diameter of ~25°. This 0.3 kpc distant structure is a peculiar Galactic supernova remnant in that it is obviously visible only in X-rays, due to its expansion into a region of extremely low ambient density: hence, practically no optical emission or a neutral $\ion{H}{i}$shell was expected to be detectable. Here we report on the discovery of a very faint arc-like nebula on a POSS II R film copy, at the south-eastern borders of the MR. Spectroscopy revealed this filament to have a very large [$\ion{S}{ii}$]λ6716+6731/Hαratio of up to ~1.8, indicating shock excitation, and a low density of Ne< 100 cm-3. There is no hint of [$\ion{O}{iii}$] emission in the spectra. On deep wide-field direct images in Hαand in [$\ion{S}{ii}$] the nebula appears as a ~20´ long, thin (~1´), structured filament, stretching N-S. We believe that this filament belongs to the MR and became visible due to the interaction of the expanding remnant with a mild density increase in the interstellar medium. Only one other possible optical filament of the MR has been reported in the literature, but no spectrum was provided.

Published
2006
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259. The Disk and Environment of the Herbig B[CLC]e[/CLC] Star HD 100546

Author

Grady, C. A., primary, Polomski, E. F., additional, Henning, Th., additional, Stecklum, B., additional, Woodgate, B. E., additional, Telesco, C. M., additional, Piña, R. K., additional, Gull, T. R., additional, Boggess, A., additional, Bowers, C. W., additional, Bruhweiler, F. C., additional, Clampin, M., additional, Danks, A. C., additional, Green, R. F., additional, Heap, S. R., additional, Hutchings, J. B., additional, Jenkins, E. B., additional, Joseph, C., additional, Kaiser, M. E., additional, Kimble, R. A., additional, Kraemer, S., additional, Lindler, D., additional, Linsky, J. L., additional, Maran, S. P., additional, Moos, H. W., additional, Plait, P., additional, Roesler, F., additional, Timothy, J. G., additional, and Weistrop, D., additional

Published
2001
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260. The extraordinarily bright optical afterglow of GRB 991208 and its host galaxy

Author

Castro-Tirado, A. J., primary, Sokolov, V. V., additional, Gorosabel, J., additional, Castro Cerón, J. M., additional, Greiner, J., additional, Wijers, R. A. M. J., additional, Jensen, B. L., additional, Hjorth, J., additional, Toft, S., additional, Pedersen, H., additional, Palazzi, E., additional, Pian, E., additional, Masetti, N., additional, Sagar, R., additional, Mohan, V., additional, Pandey, A. K., additional, Pandey, S. B., additional, Dodonov, S. N., additional, Fatkhullin, T. A., additional, Afanasiev, V. L., additional, Komarova, V. N., additional, Moiseev, A. V., additional, Hudec, R., additional, Simon, V., additional, Vreeswijk, P., additional, Rol, E., additional, Klose, S., additional, Stecklum, B., additional, Zapatero-Osorio, M. R., additional, Caon, N., additional, Blake, C., additional, Wall, J., additional, Heinlein, D., additional, Henden, A., additional, Benetti, S., additional, Magazzù, A., additional, Ghinassi, F., additional, Tommasi, L., additional, Bremer, M., additional, Kouveliotou, C., additional, Guziy, S., additional, Shlyapnikov, A., additional, Hopp, U., additional, Feulner, G., additional, Dreizler, S., additional, Hartmann, D., additional, Boehnhardt, H., additional, Paredes, J. M., additional, Martí, J., additional, Xanthopoulos, E., additional, Kristen, H. E., additional, Smoker, J., additional, and Hurley, K., additional

Published
2001
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262. The Very Red Afterglow of GRB 000418: Further Evidence for Dust Extinction in a Gamma‐Ray Burst Host Galaxy

Author

Klose, S., primary, Stecklum, B., additional, Masetti, N., additional, Pian, E., additional, Palazzi, E., additional, Henden, A. A., additional, Hartmann, D. H., additional, Fischer, O., additional, Gorosabel, J., additional, Sanchez‐Fernandez, C., additional, Butler, D., additional, Ott, Th., additional, Hippler, S., additional, Kasper, M., additional, Weiss, R., additional, Castro‐Tirado, A., additional, Greiner, J., additional, Bartolini, C., additional, Guarnieri, A., additional, Piccioni, A., additional, Benetti, S., additional, Ghinassi, F., additional, Magazzu, A., additional, Hurley, K., additional, Cline, T., additional, Trombka, J., additional, McClanahan, T., additional, Starr, R., additional, Goldsten, J., additional, Gold, R., additional, Mazets, E., additional, Golenetskii, S., additional, Noeske, K., additional, Papaderos, P., additional, Vreeswijk, P. M., additional, Tanvir, N., additional, Oscoz, A., additional, Munoz, J. A., additional, and Castro Ceron, J. M., additional

Published
2000
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263. Evidence for a Supernova in Reanalyzed Optical and Near‐Infrared Images of GRB 970228

Author

Galama, T. J., primary, Tanvir, N., additional, Vreeswijk, P. M., additional, Wijers, R. A. M. J., additional, Groot, P. J., additional, Rol, E., additional, van Paradijs, J., additional, Kouveliotou, C., additional, Fruchter, A. S., additional, Masetti, N., additional, Pedersen, H., additional, Margon, B., additional, Deutsch, E. W., additional, Metzger, M., additional, Armus, L., additional, Klose, S., additional, and Stecklum, B., additional

Published
2000
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271. Review of the Calar Alto Comet Campaign

Author

Herbst, T.M., primary, Hamilton, D.P., additional, Böhnhardt, H., additional, Ortiz-Moreno, J.L., additional, Richichi, A., additional, Birkle, K., additional, Calamai, G., additional, Fiedler, A., additional, Mantel, K.-H., additional, Stecklum, B., additional, Thiele, U., additional, Nicholson, P.D., additional, and Kim, S.J., additional

Published
1995
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274. The Earliest Phases of Star Formation (EPoS): a Herschel key project The thermal structure of low-mass molecular cloud cores.

Author

Launhardt, R., Stutz, A. M., Schmiedeke, A., Henning, Th., Krause, O., Balog, Z., Beuther, H., Birkmann, S., Hennemann, M., Kainulainen, J., Khanzadyan, T., Linz, H., Lippok, N., Nielbock, M., Pitann, J., Ragan, S., Risacher, C., Schmalzl, M., Shirley, Y. L., and Stecklum, B.

Subjects
STAR formation, INTERSTELLAR medium, LOW mass stars, PROTOSTARS, SPECTRAL energy distribution
Abstract

Context. The temperature and density structure of molecular cloud cores are the most important physical quantities that determine the course of the protostellar collapse and the properties of the stars they form. Nevertheless, density profiles often rely either on the simplifying assumption of isothermality or on observationally poorly constrained model temperature profiles. The instruments of the Herschel satellite provide us for the first time with both the spectral coverage and the spatial resolution that is needed to directly measure the dust temperature structure of nearby molecular cloud cores. Aims. With the aim of better constraining the initial physical conditions in molecular cloud cores at the onset of protostellar collapse, in particular of measuring their temperature structure, we initiated the guaranteed time key project (GTKP) "The Earliest Phases of Star Formation" (EPoS) with the Herschel satellite. This paper gives an overview of the low-mass sources in the EPoS project, the Herschel and complementary ground-based observations, our analysis method, and the initial results of the survey. Methods. We study the thermal dust emission of 12 previously well-characterized, isolated, nearby globules using FIR and submm continuum maps at up to eight wavelengths between 100 μm and 1.2 mm. Our sample contains both globules with starless cores and embedded protostars at different early evolutionary stages. The dust emission maps are used to extract spatially resolved SEDs, which are then fit independently with modified blackbody curves to obtain line-of-sight-averaged dust temperature and column density maps. Results. We find that the thermal structure of all globules (mean mass 7 Mϕ) is dominated by external heating from the interstellar radiation field and moderate shielding by thin extended halos. All globules have warm outer envelopes (14-20 K) and colder dense interiors (8-12 K) with column densities of a few 1022 cm-2. The protostars embedded in some of the globules raise the local temperature of the dense cores only within radii out to about 5000 AU, but do not significantly affect the overall thermal balance of the globules. Five out of the six starless cores in the sample are gravitationally bound and approximately thermally stabilized. The starless core in CB 244 is found to be supercritical and is speculated to be on the verge of collapse. For the first time, we can now also include externally heated starless cores in the Lsmm/Lbol vs. Tbol diagram and find that Tbol < 25 K seems to be a robust criterion to distinguish starless from protostellar cores, including those that only have an embedded very low-luminosity object. [ABSTRACT FROM AUTHOR]

Published
2013
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277. UWISH2 - the UKIRT Widefield Infrared Survey for H2.

Author

Froebrich, D., Davis, C. J., Ioannidis, G., Gledhill, T. M., Takami, M., Chrysostomou, A., Drew, J., Eislöffel, J., Gosling, A., Gredel, R., Hatchell, J., Hodapp, K. W., Kumar, M. S. N., Lucas, P. W., Matthews, H., Rawlings, M. G., Smith, M. D., Stecklum, B., Varricatt, W. P., and Lee, H. T.

Subjects
INFRARED imaging, MOLECULAR clouds, STAR formation, SUPERNOVA remnants, ASTRONOMICAL photometry, ENERGY bands
Abstract

ABSTRACT We present the goals and preliminary results of an unbiased, near-infrared, narrow-band imaging survey of the first galactic quadrant (10° < l < 65°; −13 < b < +13). This area includes most of the giant molecular clouds and massive star forming regions in the Northern hemisphere. The survey is centred on the 1-0 S(1) rovibrational line of H 2, a proven tracer of hot, dense molecular gas in star-forming regions, around evolved stars, and in supernova remnants. The observations complement existing and upcoming photometric surveys ( Spitzer-GLIMPSE, UKIDSS-GPS, JCMT-JPS, AKARI, Herschel Hi-GAL, etc.), though we probe a dynamically active component of star formation not covered by these broad-band surveys. Our narrow-band survey is currently more than 60 per cent complete. The median seeing in our images is 0.73 arcsec. The images have a 5 σ detection limit of point sources of K∼ 18 mag and the surface brightness limit is 10 −19 W m −2 arcsec −2 when averaged over our typical seeing. Jets and outflows from both low- and high-mass young stellar objects are revealed, as are new planetary nebulae and - via a comparison with earlier K-band observations acquired as a part of the UKIDSS GPS - numerous variable stars. With their superior spatial resolution, the UWISH2 data also have the potential to reveal the true nature of many of the extended green objects found in the GLIMPSE survey. [ABSTRACT FROM AUTHOR]

Published
2011
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280. Outflows, Disks, and Stellar Content in a Region of High-Mass Star Formation: G5.89–0.39 with Adaptive OpticsBased on observations made with ESO Telescopes at La Silla and Paranal under programs ID:64.I-0532 and ID:73.C-0178. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC).

Author

Puga, E., Feldt, M., Alvarez, C., Henning, Th., Apai, D., Coarer, E. Le, Chalabaev, A., and Stecklum, B.

Published
2006
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288. Polarimetric studies of gamma-ray burst afterglows.

Author

Klose, S., Stecklum, B., and Fischer, O.

Subjects
*GAMMA ray bursts, *AFTERGLOW (Physics)
Abstract

We report on a target of opportunity program to study GRB afterglows based on observations with the Calar Alto 3.5-m telescope equipped with the near-infrared camera Omega Cass. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2000

289. Spectroscopic distances of 28 nearby star candidates

Author

Jahrei?, H., Meusinger, H., Scholz, R.-D., and Stecklum, B.

Abstract

Aims. Twenty eight hitherto neglected candidates for the Catalogue of Nearby Stars (CNS) were investigated to verify their classification and to improve their distance estimates. All targets had at least a preliminary status of being nearby dwarf stars based on their large proper motions and relatively faint magnitudes. Better photometric and/or spectroscopic distances were required for selecting stars for further trigonometric parallax measurements.Methods. Low-resolution spectra were obtained with NASPEC at the Tautenburg 2?m telescope and with CAFOS at the Calar Alto 2.2?m telescope. The spectral types of M-type stars were determined by direct comparison of the target's spectra with those of comparison stars of known spectral types observed with the same instrument. The classification of earlier types was performed based on comparison with published spectral libraries.Results. For most of the target stars reliable spectral types could be determined and in combination with 2MASS?photometry new improved distance estimates became available. The majority were classified as M?dwarfs including 11?stars within 25?pc. The fainter component of LDS?1365, previously thought to form a nearby common proper motion pair, is according to our results an unrelated high-velocity background star. For several other nearby common proper motion pairs our distance estimates of the fainter components are in good agreement with Hipparcos distances of the brighter components. The three stars in our sample that were previously thought to be white dwarfs (GJ?2091, GJ?2094, GJ?2098) turned out to be more distant high-velocity F- to K-type (sub)dwarfs. For the star with the largest tangential velocity (GJ?2091; vtan>500?km?s-1) we have additional evidence for its probable Galactic halo membership from a measured large radial velocity of 266?? 25?km?s-1and from its UBV?photometry indicating a low metallicity.

Published
2008

291. Measuring the ionisation fraction in a jet from a massive protostar.

Author

Purser, S. J. D., Garcia-Lopez, R., Ray, T. P., Fedriani, R., Caratti o Garatti, A., Coffey, D., Sanna, A., Tan, J. C., Stecklum, B., and Hoare, M.

Subjects
PROTOSTARS, IONIZATION (Atomic physics), JETS (Nuclear physics), ANGULAR momentum (Nuclear physics), MASS spectrometry
Abstract

It is important to determine if massive stars form via disc accretion, like their low-mass counterparts. Theory and observation indicate that protostellar jets are a natural consequence of accretion discs and are likely to be crucial for removing angular momentum during the collapse. However, massive protostars are typically rarer, more distant and more dust enshrouded, making observational studies of their jets more challenging. A fundamental question is whether the degree of ionisation in jets is similar across the mass spectrum. Here we determine an ionisation fraction of ~5–12% in the jet from the massive protostar G35.20-0.74N, based on spatially coincident infrared and radio emission. This is similar to the values found in jets from lower-mass young stars, implying a unified mechanism of shock ionisation applies in jets across most of the protostellar mass spectrum, up to at least ~10 solar masses. The ionisation fraction of protostellar jets is key to establish their true energetics. Here, the authors determine it in a jet from a high-mass young stellar object, using multi-wavelengths observations, confirming that the ionising mechanism giving rise to the radio emission originates from shocks. [ABSTRACT FROM AUTHOR]

Published
2019
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292. GRB 011121: Jet, wind and supernova -- all in one

Author

Greiner, J., Klose, S., Salvato, M., Zeh, A., Schwarz, R., Hartmann, D. H., Masetti, N., Stecklum, B., Lamer, G., Lodieu, N., Scholz, R. D., Sterken, C., Gorosabel, J., Burud, I., Rhoads, J., Mitrofanov, I., Litvak, M., Sanin, A., Grinkov, V., Andersen, M. I., Castro Cerón, J. M., Castro-Tirado, A. J., Fruchter, A., Fynbo, J. U., Hjorth, J., Kaper, L., Kouveliotou, C., Eliana Palazzi, Pian, E., Rol, E., Salamanca, I., Tanvir, N. R., Vreeswijk, P. M., Wijers, R. A. M. J., and Den Heuvel, E.

293. The polarization evolution of the optical afterglow of GRB 030329

Author

Greiner, J., Klose, S., Reinsch, K., Schmid, Hm, Sari, R., Hartmann, Dh, Kouveliotou, C., Rau, A., Palazzi, E., Straubmeier, C., Stecklum, B., Zharikov, S., Tovmassian, G., Barnbantner, O., Ries, C., Jehin, E., Henden, A., Kaas, Ss, Grav, T., Hjorth, J., Pedersen, H., Wijers, Ramj, Kaufer, A., Park, Hs, Williams, G., Olaf Reimer, Fenimore, Ee, Galassi, M., and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Abstract

Not Available

296. Recent updates on the Maser Monitoring Organisation

Author

Burns, R. A., Kobak, A., Caratti O Garatti, A., Tolmachev, A., Volvach, A., Alakoz, A., Wootten, A., Bisyarina, A., Dzodzomenyo, A., Sobolev, A., Bartkiewicz, A., Aberfelds, A., Stecklum, B., Kramer, B., Macdonald, C., Cyganowski, C., Colomer, F., Miro, C. G., Brogan, C., Li, D., Smits, D., Engels, D., Ladeyschikov, D., Johnstone, D., Elena Popova, Proven-Adzri, E., Den Heever, F., Orosz, G., Surcis, G., Wu, G., Macleod, G., Linz, H., Imai, H., Langevelde, H., Valtts, I., Shmeld, I., Chibueze, J. O., Brand, J., Kumar, J., Green, J., Vorster, J., Eislöffel, J., Kim, J., Sugiyama, K., Menten, K., Immer, K., Sunada, K., Kim, K. -T, Volvach, L., Moscadelli, L., Jordan, L., Uscanga, L., Gray, M., Szymczak, M., Olech, M., Hoare, M., Durjasz, M., Uchiyama, M., Shakhvorostova, N., Bayandina, O., Wolak, P., Gulyaev, S., Khaibrakhmanov, S., Breen, S., Goedhart, S., Casu, S., Ellingsen, S., Kurtz, S., Weston, S., Yoshihiro, T., Natusch, T., Hunter, T., Hirota, T., Baan, W., Vlemmings, W., Chen, X., Gong, Y., Yonekura, Y., Szabó, Z. M., Abraham, Z., ITA, USA, GBR, FRA, DEU, ESP, AUS, CAN, KOR, JPN, CHN, and RUS

Abstract

The Maser Monitoring Organisation (M2O) is a research community of telescope operators, astronomy researchers and maser theoreticians pursuing a joint goal of reaching a deeper understanding of maser emission and exploring its variety of uses as tracers of astrophysical events. These proceedings detail the origin, motivations and current status of the M2O, as was introduced at the 2021 EVN symposium.

299. Searching for H2 emission from protoplanetary disks using near- and mid-infrared high-resolution spectroscopy

Author

Carmona, A., van den Ancker, M. E., Henning, Th, Pavlyuchenkov, Ya, Dullemond, C. P., Goto, M., Fedele, D., Stecklum, B., F-.Thi, W., Bouwman, J., Waters, L. B. F. M., Carmona, A., van den Ancker, M. E., Henning, Th, Pavlyuchenkov, Ya, Dullemond, C. P., Goto, M., Fedele, D., Stecklum, B., F-.Thi, W., Bouwman, J., and Waters, L. B. F. M.

Abstract

The mass and dynamics of protoplanetary disks are dominated by molecular hydrogen (H2). However, observationally very little is known about the H2. In this paper, we discuss two projects aimed to constrain the properties of H2 in the disk's planet forming region (R<50AU). First, we present a sensitive survey for pure-rotational H2 emission at 12.278 and 17.035 μm in a sample of nearby Herbig Ae/Be and T Tauri stars using VISIR, ESO's VLT high-resolution mid-infrared spectrograph. Second, we report on a search for H2 ro-vibrational emission at 2.1228, 2.2233 and 2.2477 μm in the classical T Tauri star LkHα 264 and the debris disk 49 Cet employing CRIRES, ESO's VLT high-resolution near-infrared spectrograph. VISIR project: none of the sources show H2 mid-IR emission. The observed disks contain less than a few tenths of MJupiter of optically thin H2 at 150 K, and less than a few MEarth at T>300 K. % and higher T. Our non-detections are consistent with the low flux levels expected from the small amount of H2 gas in the surface layer of a Chiang and Goldreich (1997) Herbig Ae two-layer disk model. In our sources the H2 and dust in the surface layer have not significantly departed from thermal coupling (Tgas/Tdust<2) and the gas-to-dust ratio in the surface layer is very likely <1000. CRIRES project: The H2 lines at 2.1218 μm and 2.2233 μm are detected in LkHα 264. An upper limit on the 2.2477 μm H2 line flux in LkHα 264 is derived. 49 Cet does not exhibit H2 emission in any of observed lines. There are a few MMoon of optically thin hot H2 in the inner disk (0.1 AU) of LkHα 264, and less than a tenth of a MMoon of hot H2 in the inner disk of 49 Cet. The shape of the 1-0 S(0) line indicates that LkHα disk is close to face-on (i<35o). The measured 1-0 S(0)/1-0 S(1) and 2-1 S(1)/1-0 S(1) line ratios in LkHα 264 indicate that the H2 is thermally excited at T<1500 K. The lack of H2 emission in the NIR spectra of 49 Cet and the absence of Hα emission suggest that the gas in the

300. The afterglows of Swift-era gamma-ray bursts. I. Comparing pre-Swift and Swift-era long/soft (type II) GRB optical afterglows

Author

Kann D., Klose S., Zhang B., Malesani D., Nakar E., Pozanenko A., Wilson A., Butler N., Jakobsson P., Schulze S., Andreev M., Antonelli L., Bikmaev I., Biryukov V., Böttcher M., Burenin R., Cerón J., Castro-Tirado A., Chincarini G., Cobb B., Covino S., D'Avanzo P., D'Elia V., Valle M., De Ugarte Postigo A., Efimov Y., Ferrero P., Fugazza D., Fynbo J., Gålfalk M., Grundahl F., Gorosabel J., Gupta S., Guziy S., Hafizov B., Hjorth J., Holhjem K., Ibrahimov M., Im M., Israel G., Jelainek M., Jensen B., Karimov R., Khamitov I., Kiziloǧlu U., Klunko E., Kubánek P., Kutyrev A., Laursen P., Levan A., Mannucci F., Martin C., Mescheryakov A., Mirabal N., Norris J., Ovaldsen J., Paraficz D., Pavlenko E., Piranomonte S., Rossi A., Rumyantsev V., Salinas R., Sergeev A., Sharapov D., Sollerman J., Stecklum B., Stella L., Tagliaferri G., Tanvir N., Telting J., Testa V., Updike A., Volnova A., Watson D., Wiersema K., Xu D., Kann D., Klose S., Zhang B., Malesani D., Nakar E., Pozanenko A., Wilson A., Butler N., Jakobsson P., Schulze S., Andreev M., Antonelli L., Bikmaev I., Biryukov V., Böttcher M., Burenin R., Cerón J., Castro-Tirado A., Chincarini G., Cobb B., Covino S., D'Avanzo P., D'Elia V., Valle M., De Ugarte Postigo A., Efimov Y., Ferrero P., Fugazza D., Fynbo J., Gålfalk M., Grundahl F., Gorosabel J., Gupta S., Guziy S., Hafizov B., Hjorth J., Holhjem K., Ibrahimov M., Im M., Israel G., Jelainek M., Jensen B., Karimov R., Khamitov I., Kiziloǧlu U., Klunko E., Kubánek P., Kutyrev A., Laursen P., Levan A., Mannucci F., Martin C., Mescheryakov A., Mirabal N., Norris J., Ovaldsen J., Paraficz D., Pavlenko E., Piranomonte S., Rossi A., Rumyantsev V., Salinas R., Sergeev A., Sharapov D., Sollerman J., Stecklum B., Stella L., Tagliaferri G., Tanvir N., Telting J., Testa V., Updike A., Volnova A., Watson D., Wiersema K., and Xu D.

Abstract

We have gathered optical photometry data from the literature on a large sample of Swift-era gamma-ray burst (GRB) afterglows including GRBs up to 2009 September, for a total of 76 GRBs, and present an additional three pre-Swift GRBs not included in an earlier sample. Furthermore, we publish 840 additional new photometry data points on a total of 42 GRB afterglows, including large data sets for GRBs 050319, 050408, 050802, 050820A, 050922C, 060418, 080413A, and 080810. We analyzed the light curves of all GRBs in the sample and derived spectral energy distributions for the sample with the best data quality, allowing us to estimate the host-galaxy extinction. We transformed the afterglow light curves into an extinction-corrected z = 1 system and compared their luminosities with a sample of pre-Swift afterglows. The results of a former study, which showed that GRB afterglows clustered and exhibited a bimodal distribution in luminosity space, are weakened by the larger sample. We found that the luminosity distribution of the two afterglow samples (Swift-era and pre-Swift) is very similar, and that a subsample for which we were not able to estimate the extinction, which is fainter than the main sample, can be explained by assuming a moderate amount of line-of-sight host extinction. We derived bolometric isotropic energies for all GRBs in our sample, and found only a tentative correlation between the prompt energy release and the optical afterglow luminosity at 1 day after the GRB in the z = 1 system. A comparative study of the optical luminosities of GRB afterglows with echelle spectra (which show a high number of foreground absorbing systems) and those without, reveals no indication that the former are statistically significantly more luminous. Furthermore, we propose the existence of an upper ceiling on afterglow luminosities and study the luminosity distribution at early times, which was not accessible before the advent of the Swift satellite. Most GRBs feature aftergl

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