| dc.contributor.author | HARPER, GRAHAM | |
| dc.date.accessioned | 2009-09-22T12:07:10Z | |
| dc.date.available | 2009-09-22T12:07:10Z | |
| dc.date.issued | 2005 | |
| dc.date.submitted | 2005 | en |
| dc.identifier.citation | Ayres, T. R., Brown, A. and Harper, G. M. `Chandra observations of coronal emission from the early-G supergiants Alpha and Beta Aquarii? in Astrophysical Journal, 627, 2005, L53 | en |
| dc.identifier.other | Y | |
| dc.identifier.other | Y | en |
| dc.description | PUBLISHED | en |
| dc.description.abstract | We report Chandra detections of coronal X-rays from the early-G supergiants
? Aquarii (HD209750: G2 Ib) and ? Aquarii (HD204867: G0 Ib). Previous
ROSAT observations of these archetype \hybrid chromosphere" stars were in-
conclusive in the case of ? Aqr, owing to a 380 mispointing; and although clearly
detecting a source near ? Aqr, a small positional discrepancy called the iden-
ti?cation into question. The Chandra High Resolution Camera (HRC-I), with
its superior spatial resolution and sensitivity, has obtained a positive detection
of ? Aqr, and recovered faint emission at the location of ? Aqr, now well sepa-
rated from the stronger source to the SE that dominated the earlier ROSAT im-
age. The coronal LX=LC IV luminosity ratios of both supergiants are extremely
depressed relative to early-G main sequence stars, continuing the \X-ray de?-
ciency" trend originally identi?ed in late-F/early-G luminosity class III giants of
the Hertzsprung gap. | en |
| dc.description.sponsorship | This work was supported by Chandra grant G05-6010X from the Smithsonian Astro-
physical Observatory, and NASA grant NAG5-13058. Observations from the Chandra X-ray
Observatory were collected and processed at the Chandra X-ray Observatory Center, op-
erated for NASA by Smithsonian Astrophysical Observatory. This research also utilized
the SIMBAD database, maintained by CDS, Strasbourg, France; the ROSAT and XMM{
Newton public archives at the HEASARC of the NASA Goddard Space Flight Center; and
HST data from the Multimission Archive at Space Telescope (MAST), including the \Cool-
CAT" cool-star spectral catalog. We also made use of the X-ray count-rate tool provided by
HEASARC and the hydrogen column density calculator hosted by MAST. | en |
| dc.format.extent | L53 | en |
| dc.format.extent | 210716 bytes | |
| dc.format.mimetype | application/pdf | |
| dc.language.iso | en | en |
| dc.publisher | University of Colorado | en |
| dc.relation.ispartofseries | Astrophysical Journal | en |
| dc.relation.ispartofseries | 627 | en |
| dc.rights | Y | en |
| dc.subject | Stars: individual | X-rays: coronae | ultraviolet: spectra | en |
| dc.title | Chandra observations of coronal emission from the early-G supergiants Alpha and Beta Aquarii | en |
| dc.type | Journal Article | en |
| dc.type.supercollection | scholarly_publications | en |
| dc.type.supercollection | refereed_publications | en |
| dc.identifier.peoplefinderurl | http://people.tcd.ie/harperg | |
| dc.identifier.rssuri | http://casa.colorado.edu/~gmh/pubs/abh2005.pdf | |
| dc.contributor.sponsor | NASA | |
| dc.identifier.uri | http://hdl.handle.net/2262/33128 | |
