Multiwavelength observation of a new black hole candidate: EXS 1737.9-2952

We report a multiwavelength analysis of an unusual high-energy transient: EXS 1737.9-2952. Due to the features this source exhibited in the hard X-ray domain similar to another source in the Galactic center region (1E1740.9 - 2952), and in order to study the molecular gas toward this X-ray source, we performed an observation of the EXS region in 1993 August, using the Swedish-ESO Submillimeter Telescope (SEST) located in La Silla (Chilean Andes). We observed a cloud, at the "forbidden" velocity of 135 km s-1, using 12CO (1-0) transitions, giving a maximum column density of 8 × 1021 cm-2. In 1994 we conducted other observations to search for higher density regions inside the cloud, using HCO+ and CS lines, but they were unsuccessful: we concluded that the cloud could be associated with the X-ray source and its mean density is of the order of ≈103 cm-3. In 1994 April, we performed a set of observations of the field containing EXS, at 20 cm and 6 cm, using the VLA in its A configuration, and found four possible radio candidates for an association with the EXS X-ray source, one of them (source 3) being extended, exhibiting a head-tail morphology, and a having a thermal spectrum with a spectral index ≈-0.7. We reproduced our observation in 1994 November and December, using the C configuration at 6 cm, in order to investigate on possible variability and extension of these sources and found a marginal indication in the 20 cm image that source 3 may have a weak second component displaced about 15". Nevertheless, this indication is too faint to associate this source definitely with EXS since no significant variation was detected. In addition, during the 1994 November-December observation, two more extended sources were detected but their association with EXS is unlikely. We also analyzed the Einstein/IPC image of the 5 σ EXS error box which does not exhibit, at the time of the observation, any significant low-energy X-ray counterpart to EXS. A nearby pulsar PSR 1737-30 in the ROSAT catalog is outside this error box. Finally, IRAS maps of the EXS region do not show any IR contribution at the location of the radio sources. We conclude that (1) EXS 1737.9-2952 is a high-energy transient, (2) a persistent counterpart at other wavelengths is not demonstrated, and (3) EXS, when flaring, as well as other GC gamma-ray sources, could possibly contribute to the 511 keV bulge emission

The Distance of the Soft Gamma Repeater SGR 1806-20

We present CO(J=1-0) observations in the direction of the Soft Gamma Repeater SGR 1806-20 with the SEST telescope. We detected several molecular clouds, and we discuss in this paper the implications of these observations for the distance to the X-ray counterpart AX 1805.7-2025, the supernova remnant G10.0-0.3 and the very luminous O9-B2 star detected in the line of sight. The distance of SGR 1806-20 is estimated to be 14.5 +/- 1.4 kpc and this Soft Gamma Repeater is very likely associated with one of the brightest HII regions in the Galaxy, W31. The large size of G10.0-0.3 (25 x 38 pc) for a young supernova remnant possibly powered by a central pulsar (AX 1805.7-2025) indicates that G10.0-0.3 could be expanding in the very low density region produced by the wind of the blue star.Comment: 20 pages, four postscript figures, LaTeX. To appear in Astrophysical Journal, 1997, in pres

An 8 year nationwide prospective registration of non-consented HIV testing in Belgium.

&lt;p&gt;&lt;b&gt;BACKGROUND: &lt;/b&gt;Little information is available on the number of HIV tests that are carried out without the patient&#039;s consent. The aim of this study was to find out about the number of HIV tests for which the specific consent of the patient was not obtained and to describe the circumstances in which these tests were carried out.&lt;/p&gt;&lt;p&gt;&lt;b&gt;METHODS: &lt;/b&gt;Since 1993 a representative network of sentinel general practitioners (GPs) has recorded data about requests for HIV tests, risk behaviour and the patient&#039;s awareness about the test.&lt;/p&gt;&lt;p&gt;&lt;b&gt;RESULTS: &lt;/b&gt;In total 11,660 HIV tests were recorded and for 3628 tests the question about patient awareness was completed. Although non-consensual HIV testing (NHT) is against European guidelines on informed consent, 453 tests were performed without informed consent. Of the 292 participating GPs, 17.5 per cent never completed the question about the patient&#039;s awareness and 35.6 per cent performed at least one non-consensual HIV test. For 28.9 per cent of NHT, no risk behaviour for HIV infection was identified and for 43.4 per cent the risk behaviour was unknown. NHT was recurrent for patients with suggestive symptoms (22.7 per cent), patients consulting for a check-up (21.1 per cent) and women consulting for antenatal care (12.8 per cent).&lt;/p&gt;&lt;p&gt;&lt;b&gt;CONCLUSION: &lt;/b&gt;Never before have figures been available about NHT forthcoming from a prospective registration including such a large number of tested subjects. Physicians should be reminded once more about the unacceptability of NHT. Instead of performing a non-consensual HIV test, physicians should invest more time in pre-test counselling, especially in those patients with a higher risk or with suggestive symptoms for HIV.&lt;/p&gt;</p

Multiwavelength observation of a new black hole candidate: EXS 1737.9-2952

We report a multiwavelength analysis of an unusual high-energy transient: EXS 1737.9-2952. Due to the features this source exhibited in the hard X-ray domain similar to another source in the Galactic center region (1E1740.9 - 2952), and in order to study the molecular gas toward this X-ray source, we performed an observation of the EXS region in 1993 August, using the Swedish-ESO Submillimeter Telescope (SEST) located in La Silla (Chilean Andes). We observed a cloud, at the ``forbidden'' velocity of 135 km s^-1, using ^12CO (1-0) transitions, giving a maximum column density of 8 x 10^21 cm^-2. In 1994 we conducted other observations to search for higher density regions inside the cloud, using HCO+ and CS lines, but they were unsuccessful: we concluded that the cloud could be associated with the X-ray source and its mean density is of the order of ~10^3 cm^-3. In 1994 April, we performed a set of observations of the field containing EXS, at 20 cm and 6 cm, using the VLA in its A configuration, and found four possible radio candidates for an association with the EXS X-ray source, one of them (source 3) being extended, exhibiting a head-tail morphology, and a having a thermal spectrum with a spectral index ~ -0.7. We reproduced our observation in 1994 November and December, using the C configuration at 6 cm, in order to investigate on possible variability and extension of these sources and found a marginal indication in the 20 cm image that source 3 may have a weak second component displaced about 15". Nevertheless, this indication is too faint to associate this source definitely with EXS since no significant variation was detected. In addition, during the 1994 November-December observation, two more extended sources were detected but their association with EXS is unlikely. We also analyzed the Einstein/IPC image of the 5 sigma EXS error box which does not exhibit, at the time of the observation, any significant low-energy X-ray counterpart to EXS. A nearby pulsar PSR 1737-30 in the ROSAT catalog is outside this error box. Finally, IRAS maps of the EXS region do not show any IR contribution at the location of the radio sources. We conclude that (1) EXS 1737.9-2952 is a high-energy transient, (2) a persistent counterpart at other wavelengths is not demonstrated, and (3) EXS, when flaring, as well as other GC gamma-ray sources, could possibly contribute to the 511 keV bulge emission