| 1. |
- Dunham, I, et al.
(författare)
-
The DNA sequence of human chromosome 22
- 1999
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 402:6761, s. 489-495
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Tidskriftsartikel (refereegranskat)
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| 2. |
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| 3. |
- Crenshaw, D. M., et al.
(författare)
-
Multiwavelength observations of short-timescale variability in NGC 4151. I. Ultraviolet observations
- 1996
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 470:1, s. 322-335335
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Tidskriftsartikel (refereegranskat)abstract
- Presents the results of an intensive ultraviolet monitoring campaign on the Seyfert 1 galaxy NGC 4151, as part of an effort to study its short-timescale variability over a broad range in wavelength. The nucleus of NGC 4151 was observed continuously with the International Ultraviolet Explorer for 9.3 days, yielding a pair of LWP and SWP spectra every ~70 minutes, and during 4 hr periods for 4 days prior to and 5 days after the continuous-monitoring period. The sampling frequency of the observations is an order of magnitude higher than that of any previous UV monitoring campaign on a Seyfert galaxy. The continuum fluxes in bands from 1275 to 2688 Aring went through four significant and well-defined ldquoeventsrdquo of duration 2-3 days during the continuous-monitoring period. The authors find that the amplitudes of the continuum variations decrease with increasing wavelength, which extends a general trend for this and other Seyfert galaxies to smaller timescales (i.e., a few days). The continuum variations in all the UV bands are simultaneous to within an accuracy of ~0.15 days, providing a strict constraint on continuum models. The emission-line light curves show only one major event during the continuous monitoring (a slow rise followed by a shallow dip) and do not correlate well with continuum light curves over the short duration of the campaign, because the timescale for continuum variations is apparently smaller than the response times of the emission lines
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| 4. |
- Edelson, R. A., et al.
(författare)
-
Multiwavelength observations of short-timescale variability in NGC 4151. IV. Analysis of multiwavelength continuum variability
- 1996
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 470:1, s. 364-377377
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Tidskriftsartikel (refereegranskat)abstract
- For pt.III see ibid., vol.470, no.1, p.349-63 (1996). Combines data from the three preceding papers in order to analyze the multi wave-band variability and spectral energy distribution of the Seyfert 1 galaxy NGC 4151 during the 1993 December monitoring campaign. The source, which was near its peak historical brightness, showed strong, correlated variability at X-ray, ultraviolet, and optical wavelengths. The strongest variations were seen in medium-energy (~1.5 keV) X-rays, with a normalized variability amplitude (NVA) of 24%. Weaker (NVA=6%) variations (uncorrelated with those at lower energies) were seen at soft gamma-ray energies of ~100 keV. No significant variability was seen in softer (0.1-1 keV) X-ray bands. In the ultraviolet/optical regime, the NVA decreased from 9% to 1% as the wavelength increased from 1275 to 6900 Aring. These data do not probe extreme ultraviolet (1200 Aring to 0.1 keV) or hard X-ray (250 keV) variability. The phase differences between variations in different bands were consistent with zero lag, with upper limits of lsim0.15 day between 1275 Aring and the other ultraviolet bands, lsim0.3 day between 1275 Aring and 1.5 keV, and lsim1 day between 1275 and 5125 Aring. These tight limits represent more than an order of magnitude improvement over those determined in previous multi-wave-band AGN monitoring campaigns. The ultraviolet fluctuation power spectra showed no evidence for periodicity, but were instead well fitted with a very steep, red power law (ales-2.5)
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| 5. |
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| 6. |
- Andrés, E. C., et al.
(författare)
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The AMANDA neutrino telescope
- 1999
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Ingår i: Nuclear physics B, Proceedings supplements. - 0920-5632 .- 1873-3832. ; 77:1-3, s. 474-485
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Tidskriftsartikel (refereegranskat)abstract
- With an effective telescope area of order 104 m2 for TeV neutrinos, a threshold near ∼50 GeV and a pointing accuracy of 2.5 degrees per muon track, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe early results on the calibration of natural deep ice as a particle detector as well as on AMANDA's performance as a neutrino telescope.
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| 7. |
- Bay, R. C., et al.
(författare)
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The AMANDA neutrino telescope and the indirect search for dark matter : AMANDA Colaboration
- 1998
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Ingår i: Physics reports. - : Elsevier. - 0370-1573 .- 1873-6270. ; 307:1-4, s. 243-252
-
Tidskriftsartikel (refereegranskat)abstract
- With an effective telescope area of order 104m2, a threshold of ~50GeV and a pointing accuracy of 2.5°, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe its performance, focussing on the capability to detect halo dark matter particles via their annihilation into neutrinos.
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| 8. |
- Miller, T. C., et al.
(författare)
-
Particle astrophysics in antarctica
- 1996
-
Ingår i: International School of Cosmic Ray Astrophysics: 10th Course: Toward the Millennium in Astrophysics: Problems and Prospects 16-26 Jun 1996. Erice, Italy. ; , s. 157-166
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Konferensbidrag (refereegranskat)
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| 9. |
- Wischnewski, R., et al.
(författare)
-
The AMANDA neutrino detector
- 1999
-
Ingår i: Nuclear physics B, Proceedings supplements. - : Elsevier. - 0920-5632 .- 1873-3832. ; 75:1-2, s. 412-414
-
Tidskriftsartikel (refereegranskat)abstract
- The first stage of the AMANDA High Energy Neutrino Detector at the South Pole, the 302 PMT array AMANDA-B with an expected effective area for TeV neutrinos of ∼ 104 m2, has been taking data since 1997. Progress with calibration, investigation of ice properties, as well as muon and neutrino data analysis are described. The next stage 20-string detector AMANDA-II with ∼800 PMTs will be completed in spring 2000.
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| 10. |
- Andres, E., et al.
(författare)
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AMANDA : Status, results and future
- 1999
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Ingår i: Proceedings, 8th International Workshop, Venice, Italy, February 23-26, 1999. Vol. 1, 2. ; , s. 63-79
-
Konferensbidrag (refereegranskat)abstract
- We review the status of the AMANDA neutrino telescope. We present resultsobtained from the four-string prototype array AMANDA-B4 and describe themethods of track reconstruction and neutrino event separation. We give also firstresults of the analysis of the 10-string detector AMANDA-B10, in particular onatmospheric neutrinos and the search for magnetic monopoles. We sketch thefuture schedule on the way to a cube kilometer telescope at the South Pole,ICECUBE.
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