1,723,219 research outputs found
Vital Files 4001-6388
No full textPart 3/3 of the VitalDB open dataset: 4001.vital - 6388.vital; 2388 files, 36.9G
Vital Files 4001-6388
No full textPart 3/3 of the VitalDB open dataset: 4001.vital - 6388.vital; 2388 files, 36.9G
Vital Files 4001-6388
No full textPart 3/3 of the VitalDB open dataset: 4001.vital - 6388.vital; 2388 files, 36.9G
NGC 6388: XMM-Newton and Chandra observation
No full textContext: By studying the optical brightness surface density of the globular cluster NGC 6388, it has been recently proposed that it harbors a central intermediate-mass black hole with mass ≃ 5.7×103 M⊙.
Aims: We expect that the compact object in the center of NGC 6388 emits radiation in the X-ray band as a consequence of the accretion from the surrounding matter. We searched for XMM-Newton and Chandra observations towards NGC 6388 to test this hypothesis.
Methods: We determine both the hardness ratios and luminosity with a minimum set of assumptions for each of the identified field sources.
Results: The Chandra satellite disentangles several point-like X-ray sources, probably low mass X-ray binaries, well within the core radius of the globular cluster. However, three of them, coinciding with the cluster center of gravity, remain unresolved. Their total luminosity is L_X^Obs ≃ 2.7×1033 erg s-1. If one of these sources is the X-ray counterpart of the intermediate-mass black hole in NGC 6388, the corresponding upper limit on the accretion efficiency, with respect to the Eddington luminosity, is 3×10-9. This measurement could be tightened if moderately deep radio observations of the field were performed.
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Deep <i>HST</i> photometry of NGC 6388
No full textUsing the Hubble Space Telescope, we have obtained the first color-magnitude diagram (CMD) to reach the main-sequence turnoff of the Galactic globular cluster NGC 6388. From a comparison between the cluster CMD and that of 47 Tucanae, we find that the bulk of the stars in these two clusters have nearly the same age and chemical composition. On the other hand, our results indicate that the blue horizontal branch and RR Lyrae components in NGC 6388 are intrinsically overluminous, which must be due to one or more, still undetermined, noncanonical second parameter(s) affecting a relatively minor fraction of the stars in NGC 6388
The globular cluster NGC 6388: XMM-Newton and Chandra observations
No full textBy studying the optical brightness surface density of the globular cluster NGC 6388, it has been
recently proposed that it harbors a central intermediate-mass black hole with mass 5.7×10 3 M .
We expect that the compact object in the center of NGC 6388 emits radiation in the X-ray band
as a consequence of the accretion from the surrounding matter. We searched for XM M -Newton
and Chandra observations towards NGC 6388 to test this hypothesis. The Chandra satellite
disentangles several point-like X-ray sources, probably low mass X-ray binaries, well within the
core radius of the globular cluster. However, three of them, coinciding with the cluster center
of gravity, remain unresolved. Their total luminosity is LObs
2.7 × 1033 erg s−1 . If one of
X
these sources is the X-ray counterpart of the intermediate-mass black hole in NGC 6388, the
corresponding upper limit on the accretion efficiency, with respect to the Eddington luminosity, is
3 × 10−9 . This measurement could be tightened if moderately deep radio observations of the field
were performed
The high energy view of NGC 6388: hints for an IMBH?
No full textOptical observations suggest that the globular cluster NGC 6388 may harbor a central intermediate-mass black hole with mass of about 5.7×103 M⊙. We review the past X-ray and radio observations conducted towards NGC 6388 with particular attention to the high energy transient IGRJ17361-4441 recently obsereved by INTEGRAL satellite
Deep HST Photometry of NGC 6388: Age and Horizontal Branch Luminosity
Get PDFWe present the first deep color-magnitude diagram (CMD) of the Galactic globular cluster NGC 6388, obtained with the Hubble Space Telescope, that is able to reach the main-sequence turnoff point of the cluster. From a detailed comparison between the cluster CMD and that of 47 Tucanae (NGC 104), we find that the bulk of the stars in these two clusters have nearly the same age and chemical composition. On the other hand, our results indicate that the blue horizontal branch and RR Lyrae components in NGC 6388 are intrinsically over-luminous, which must be due to one or more, still undetermined, non-canonical second parameter(s) affecting a relatively minor fraction of the stars in NGC 6388
XMM-Newton and Chandra observations of the globular cluster NGC 6388
No full textContext: By studying the optical brightness surface density of the globular cluster NGC 6388, it has been recently proposed that it harbors a central intermediate-mass black hole with mass ≃ 5.7×103 Msun.
Aims: We expect that the compact object in the center of NGC 6388 emits radiation in the X-ray band as a consequence of the accretion from the surrounding matter. We searched for XMM-Newton and Chandra observations towards NGC 6388 to test this hypothesis.
Methods: We determine both the hardness ratios and luminosity with a minimum set of assumptions for each of the identified field sources.
Results: The Chandra satellite disentangles several point-like X-ray sources, probably low mass X-ray binaries, well within the core radius of the globular cluster. However, three of them, coinciding with the cluster center of gravity, remain unresolved. Their total luminosity is L_X^Obs ≃ 2.7×1033 erg s-1. If one of these sources is the X-ray counterpart of the intermediate-mass black hole in NGC 6388, the corresponding upper limit on the accretion efficiency, with respect to the Eddington luminosity, is 3×10-9. This measurement could be tightened if moderately deep radio observations of the field were performed
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