J/AJ/108/538ivo://CDS.VizieR/J/AJ/108/538doi:10.26093/cds/vizier.51080538CDSPreston G.W.Beers T.C.Shectman S.A.2023-04-06T16:50:09Z2005-12-17T11:42:03ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frchemically-peculiar-starsvisible-astronomybroad-band-photometryradial-velocityFrom analysis of a photometrically selected sample of 175 metal-poor field stars with main sequence gravities (hereafter BMPs) and UBV colors blueward of the most metal-poor globular cluster main-sequence turnoffs, 0.15<(B-V)_0_<0.35, and properties of the candidate lists of the HK objective prism survey, we calculate the space density and a suitably defined specific frequency of BMPs within ~2kpc of the Sun. We consider two cases. If we adopt the luminosities and color distribution of globular cluster blue stragglers (hereafter BS) for BMPs, the BMP space density, is ~350kpc^-3^, from which we obtain a specific frequency S(BMP)~8, a value 9 times larger than that of BSs in globular clusters. From this result, we conclude that cluster-type BSs are but a minor component of the field BMPs and that the remainder must be of a different nature. If we adopt luminosities of metal-poor models halfway between the Zero Age Main Sequence and the phase of core hydrogen exhaustion, we obtain a space density of 450(+300,-150)kpc^-3^ and a specific frequency S(BMP)=10(+5,-3). From a subsample of 107 BMPs with available radial velocities we derive a galactic rotation of 128km/s and an isotropic velocity dispersion of {sigma}~90km/s, values intermediate between those of halo and thick-disk populations. From analysis of a larger sample of stars on 0.15<(B-V)0<0.35 binned by a crude line-blanketing parameter, we find that our results are insensitive to adopted BMP selection criteria: none of these subsamples of A- and early F-type stars above the galactic plane possess disk kinematics. The region of the UBV two-color diagram occupied by BMPs could be populated by metal-deficient, main-sequence gravity stars with ages substantially younger than those of the metal-poor halo. Because we cannot imagine how or where the observed local population of BMPs could have been produced within our galaxy during the past 3 to 10Gyr, we suggest that BMPs are the bluest members of metal-poor intermediate-age main sequences accreted, probably, from dwarf spheroidal satellites of the Milky Way during the past 10Gyr. We discuss observational consequences of this suggestion.1994AJ....108..538Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/108/538CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/87/1515 : UBV photometry of AB stars in halo (Pier, 1982)J/ApJS/53/791 : Spectroscopy of AB stars in halo (Pier, 1983)J/AJ/90/2089 : Stars of very low metal abundance. (Beers+, 1985)J/PASP/102/1392 : UBV photometry from HK survey. (Doinidis+ 1990)J/PASP/103/973 : Photoelectric UBV from HK survey. (Doidinis+ 1991)J/ApJS/76/1001 : UBV photometry of HK survey stars (Preston+, 1991)J/AJ/103/267 : Spectrocopy of hot stars in galactic halo (Beers+ 1992)J/AJ/103/1987 : Stars of very low metal abundance (Beers+ 1992)J/AJ/108/268 : HK survey emission-line candidates positions (Beers+ 1994)J/AJ/112/1188 : HK survey emission-line candidates (Beers+ 1996)J/AJ/117/2329 : Spectroscopy of hot stars in the halo. (Wilhelm+, 1999)J/ApJS/123/639 : UBV photometry of metal-weak candidates (Norris+, 1999)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/108/538https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/108/538http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/108/538https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/108/538https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/108/538http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/108/538GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/108/538/table1 (BMP stars identified photometrically in the HK survey)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/108/538/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/108/538/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/108/538/table1?GETtext/xml+votable180.050000true13.0483547-11.07733190.005555555555555556Cone search capability for table J/AJ/108/538/ubv (UBV observations of HK survey stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/108/538/ubv?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/108/538/ubv?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/108/538/ubv?GETtext/xml+votable180.050000true218.5620833-20.18055560.0055555555555555565/11055 11694 6/16406 16413-16415 16423 16431-16432 16435 16441 16458 16470 16512 16515 16519 16521-16522 16526 16537 16540 16564 16567 16595 16604 16606 16609 16657 16664 16679 16682 16684 16689 16707 16711 16726 16788 16797 16832 16887 17178-17179 17189 17495 17497 17528 17537 17549 17570 17609 17668 17964 18472 18476 18488 18490 18508 18527 18531 18560 18565 18577 18581 18583 18615 18628 18707 18742 18765 18767 18776 18780 18802 18965 18973 19017 30949-30951 30959 30971 30973 31240 31279 31289 31375 31383 31386-31389 31391 31393 31420 33471 33529 33634 33642 33685 33696 33728 34836 34902-34903 34905 35519 35599 35601 35636 35638 35646 35717 35726 35741 35752 35756 35767 35823 36630 36642-36643 36652 36670 36687 36739-36740 36763 36776 36780 44258 44262 44266 44565 44567 44609 44612 44615 44617 44620-44621 44623-44625 44627 44633 44644-44645 44660 44883 44892 45400 45406 45417 45419 45428 45434 45459 45463 45466 45469 45477 45480 45484 45488 45490 45492-45494 45505 45515 45538 45693 45711 45719 45722 45733 45745 45747 45752-45753 45755 45788 45797 45799 45803 45817 45822 45838 46089 46317 46319 46330 46456 46458 46461 46463 46535 46542 46545-46546 46549-46551 46559 46562 46566 46575-46576 46585 46641 46643 46646 46649 46660-46661 46672 46674 46680 46690 46751 46764-46766 46768 46770 46773 46787 46797 46826 46847 46850 46857 47175 47180 47185 47192 47194 47205 47305 47312-47313 47320 47329 47332-47333 47335 47391 47413-47415 47417 47420 47424 47434-47435 47451 47458-47459 47461 47477 47479 47481 47503 47510 47514 47517 47519 47538 47540 47543 47556 47562 47568 48129 48131 48134 48140 48143 48151 48153 48159 48181 48212-48213 48313 48315-48316 48319 48509 48518-48519 48521 48524 48527-48528 48537 48539 48613 48656 48658 48660-48661 48664 48669 48706 48711 48719-48720 48726 48732 48766 48845 48848 48852 48856 48858 48861-48862 48880https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/108/538?format=asciiOpticaldefaultJ/AJ/108/538/table1BMP stars identified photometrically in the HK surveyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBPS-CSStar identification in HK survey (field-number)charGLONGalactic longitudedegGLATGalactic latitudedegfloatE(B-V)(B-V) colour excess adopted estimatemagfloatV0Reddening-corrected apparent V magnitudemagfloat(B-V)0Reddening-corrected B-V colour indexmagfloat(U-B)0Reddening-corrected U-B colour indexmagfloatD0Color parameter (1)floatHRV? Heliocentric radial velocitykm/sintnullabler_HRV? Reference for heliocentric radial velocity (2)intnullabler_UBV? Reference for UBV data (2)intnullableSimbadSimbad column added by the CDSchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/AJ/108/538/ubvUBV observations of HK survey starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintnSimbad column added by the CDScharBPS-CSStar identification in HK survey (field-number)charVmagJohnson V magnitudemagfloatB-VJohnson B-V colour indexmagfloatU-BJohnson colour indexmagfloatSimbadSimbad column added by the CDSchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main