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I. F. Mirabel 《Astrophysics and Space Science》1976,39(2):415-417
A search for neutral hydrogen in the velocity range –300>V>–1000 km s–1 has been made in the zone around the galactic nucleus. Observations of 100 points reveal no neutral hydrogen at such high velocities, with brightness temperatures exceeding 0.25 K in the latitude range |b|<1°, and 0.20 K for |b|1°. 相似文献
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The chemical composition of fogwater has been studied in the city of Strasbourg (France) from 1990 to 1999. During these years, fogwater samples have been collected and analysed for major ions and trace metals. This paper reports on the analysis of the collected dataset. The analysis revealed a significant decrease in acidity of approximately one pH unit over the course of the study. This decrease in acidity appears to be linked to a decrease in SO2(g) and the resulting SO42−. Trace metal concentrations have also strongly decreased over the 10-year period. Pb concentrations, following the elimination of leaded gasoline, decreased by more than one order of magnitude. 相似文献
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We have carried out radio studies of the surroundings of the superluminal microquasar GRS 1915+105. Our main goal was to understand the possible relation of GRS 1915+105 with two infrared/radio sources that appear symmetrically located with respect to GRS 1915+105 and aligned with the position angle of the relativistic ejecta. We have also studied a nearby supernova remnant to test if the event that created the remnant could have been the progenitor of this hard X-ray binary. 相似文献
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An anomalous velocity cloud nearl=349°,b=+3°, was investigated by Cugnon (1968). The authors made a new set of observations in order to obtain a more complete picture of the feature, including the region originally out of Cugnon's limit of observation. A comparison with optical and radio observations was made and several possibilities of interpretation as to the nature of the object were analyzed. 相似文献
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The power required to eject relativistic plasma clouds in the hard X-ray transient GRS 1915+105 is at least 100 times the luminosity of the soft-ray bursts (SGRs) that were observed by BATSE from the same region of the sky in the year 1992. We show that there are spatial, time, and spectral coincidences between GRS 1915+105 and the SGRs observed by BATSE which suggest that they are one and the same source. However, the position of the SGRs is rather uncertain and until better positions are obtained, the question on the association of GRS 1915+105 with the SGRs must remain open. 相似文献
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O. Laurent I.F. Mirabel P. Gallais M. Sauvage L. Vigroux C. Cesarsky V. Charmandaris 《Astrophysics and Space Science》1999,266(1-2):175-180
We present a new diagnostic diagram based on ISOCAMspectra (5-16 m) to distinguish the emission inducedby the active galactic nucleus (AGN) from that associated with thestar formation activity. This diagnostic based on the mid-IRcontinuum and the Unidentified Infrared Band (UIB) intensity allowsus to estimate the relative importance of the three components (HIIregions, diffuse/photo-dissociation regions (PDRs), and AGN) contained ingalaxy mid-infrared emission. In AGN spectra, we confirm the absenceof UIBs presumably photodissociated by the X-UV radiation field. Inaddition, a non-negligible continuum below 9 m commonlyassociated with emission from hot dust is present in AGNs. Adiagnostic diagram derived from these two results can be used fordetecting obscured AGNs embedded in a large concentration of dust. 相似文献
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M. Feroci P. Casella E. Costa E. Massaro P. Soffitta G. Matt T. Belloni A.J. Castro-Tirado V. Dhawan F. Frontera A. Harmon F. Mirabel G. Pooley M. Tavani 《Astrophysics and Space Science》2001,276(1):15-18
The galactic superluminal source GRS 1915+105 was observed byBeppoSAX at several occasions from October 1996 to April 2000. In April 1999 the 2–10 keV light curve showed a long series of quasi regular pulses with a recurrence time of about 50 s. Some preliminary results of a spectral analysis are presented. 相似文献
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I.F. Mirabel 《Astrophysics and Space Science》2002,281(1-2):375-378
Nearby luminous galaxies serve as templates to gain insight into the building blocks of the most luminous galaxies in the
distant universe. In this conference I have shown that the most luminous galaxies in the Local Universe are mergers of evolved
gas-rich galaxies that radiate the bulk of their energy in the mid and far-infrared. The most important implication for future
studies on the formation of galaxies at early cosmological timescales is that they will appear as luminous sub-millimeter
sources.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
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V. Charmandaris O. Laurent I.F. Mirabel P. Gallais M. Sauvage L. Vigroux C. Cesarsky 《Astrophysics and Space Science》2001,276(2-4):553-559
We present mid-infrared images and spectra of Arp 10 and Arp 118, two collisional ring galaxies observed as part of the ISOCAM
GT program CAMACTIV (P.I.: I.F. Mirabel). The observations reveal the distribution of hot dust in the galaxies and enable
us to probe the mechanisms responsible for the heating of the ISM. Unlike the peculiar mid-infrared colours recently discovered
in the Cartwheel, the prime example of a collisional ring, Arp 10 has colours typical of those found inspiral arms of late
type spirals. Similarly for Arp 118 (NGC 1144),the mid-infrared emission is associated with the regions of star formation
in the ring. Moreover, a hot continuum in the 5.1–6.7 μmrange, which is a typical mid-infrared signature of an AGN, is clearly
detected from the Seyfert 2 nucleus of the galaxy.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献