A deep view of a fossil relic in the Galactic bulge: The Globular Cluster HP 1

L. O. Kerber, M. Libralato, S. O. Souza, R. A.P. Oliveira, S. Ortolani, A. Pérez-Villegas, B. Barbuy, B. Dias, E. Bica, D. Nardiello

Resultado de la investigación: Article

3 Citas (Scopus)

Resumen

HP 1 is an α-enhanced and moderately metal-poor bulge globular cluster with a blue horizontal branch. These combined characteristics make it a probable relic of the early star formation in the innermost Galactic regions. Here, we present a detailed analysis of a deep near-infrared (NIR) photometry of HP 1 obtained with the NIR GSAOI + GeMS camera at the Gemini-South telescope. J and K S images were collected with an exquisite spatial resolution (FWHM 1/40.1 arcsec), reaching stars at two magnitudes below the MSTO. We combine our GSAOI data with archival F606W-filter HST ACS/WFC images to compute relative proper motions and select bona fide cluster members. Results from statistical isochrone fits in the NIR and optical-NIR colour-magnitude diagrams indicate an age of 12.8 +0.9-0.8 Gyr, confirming that HP 1 is one of the oldest clusters in the Milky Way. The same fits also provide apparent distance moduli in the K S and V filters in very good agreement with the ones from 11 RR Lyrae stars. By subtracting the extinction in each filter, we recover a heliocentric distance of 6.59 +0.17-0.15 kpc. Furthermore, we refine the orbit of HP 1 using this accurate distance and update and accurate radial velocities (from high-resolution spectroscopy) and absolute proper motions (from Gaia DR2), reaching mean perigalactic and apogalactic distances of 1/40.12 and 1/43 kpc, respectively.

Idioma originalEnglish
Páginas (desde-hasta)5530-5550
Número de páginas21
PublicaciónMonthly Notices of the Royal Astronomical Society
Volumen484
N.º4
DOI
EstadoPublished - 21 abr 2019
Publicado de forma externa

Huella dactilar

galactic bulge
fossils
globular clusters
near infrared
fossil
proper motion
filter
filters
early stars
stars
infrared photometry
color-magnitude diagram
radial velocity
star formation
extinction
spatial resolution
diagram
spectroscopy
cameras
telescopes

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Citar esto

Kerber, L. O., Libralato, M., Souza, S. O., Oliveira, R. A. P., Ortolani, S., Pérez-Villegas, A., ... Nardiello, D. (2019). A deep view of a fossil relic in the Galactic bulge: The Globular Cluster HP 1. Monthly Notices of the Royal Astronomical Society, 484(4), 5530-5550. https://doi.org/10.1093/mnras/stz003
Kerber, L. O. ; Libralato, M. ; Souza, S. O. ; Oliveira, R. A.P. ; Ortolani, S. ; Pérez-Villegas, A. ; Barbuy, B. ; Dias, B. ; Bica, E. ; Nardiello, D. / A deep view of a fossil relic in the Galactic bulge : The Globular Cluster HP 1. En: Monthly Notices of the Royal Astronomical Society. 2019 ; Vol. 484, N.º 4. pp. 5530-5550.
@article{858dc77470aa4879beada7e0547feb4b,
title = "A deep view of a fossil relic in the Galactic bulge: The Globular Cluster HP 1",
abstract = "HP 1 is an α-enhanced and moderately metal-poor bulge globular cluster with a blue horizontal branch. These combined characteristics make it a probable relic of the early star formation in the innermost Galactic regions. Here, we present a detailed analysis of a deep near-infrared (NIR) photometry of HP 1 obtained with the NIR GSAOI + GeMS camera at the Gemini-South telescope. J and K S images were collected with an exquisite spatial resolution (FWHM 1/40.1 arcsec), reaching stars at two magnitudes below the MSTO. We combine our GSAOI data with archival F606W-filter HST ACS/WFC images to compute relative proper motions and select bona fide cluster members. Results from statistical isochrone fits in the NIR and optical-NIR colour-magnitude diagrams indicate an age of 12.8 +0.9-0.8 Gyr, confirming that HP 1 is one of the oldest clusters in the Milky Way. The same fits also provide apparent distance moduli in the K S and V filters in very good agreement with the ones from 11 RR Lyrae stars. By subtracting the extinction in each filter, we recover a heliocentric distance of 6.59 +0.17-0.15 kpc. Furthermore, we refine the orbit of HP 1 using this accurate distance and update and accurate radial velocities (from high-resolution spectroscopy) and absolute proper motions (from Gaia DR2), reaching mean perigalactic and apogalactic distances of 1/40.12 and 1/43 kpc, respectively.",
keywords = "Galaxy: bulge, globular clusters: individual: HP 1, infrared: stars, instrumentation: adaptive optics",
author = "Kerber, {L. O.} and M. Libralato and Souza, {S. O.} and Oliveira, {R. A.P.} and S. Ortolani and A. P{\'e}rez-Villegas and B. Barbuy and B. Dias and E. Bica and D. Nardiello",
year = "2019",
month = "4",
day = "21",
doi = "10.1093/mnras/stz003",
language = "English",
volume = "484",
pages = "5530--5550",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "4",

}

Kerber, LO, Libralato, M, Souza, SO, Oliveira, RAP, Ortolani, S, Pérez-Villegas, A, Barbuy, B, Dias, B, Bica, E & Nardiello, D 2019, 'A deep view of a fossil relic in the Galactic bulge: The Globular Cluster HP 1', Monthly Notices of the Royal Astronomical Society, vol. 484, n.º 4, pp. 5530-5550. https://doi.org/10.1093/mnras/stz003

A deep view of a fossil relic in the Galactic bulge : The Globular Cluster HP 1. / Kerber, L. O.; Libralato, M.; Souza, S. O.; Oliveira, R. A.P.; Ortolani, S.; Pérez-Villegas, A.; Barbuy, B.; Dias, B.; Bica, E.; Nardiello, D.

En: Monthly Notices of the Royal Astronomical Society, Vol. 484, N.º 4, 21.04.2019, p. 5530-5550.

Resultado de la investigación: Article

TY - JOUR

T1 - A deep view of a fossil relic in the Galactic bulge

T2 - The Globular Cluster HP 1

AU - Kerber, L. O.

AU - Libralato, M.

AU - Souza, S. O.

AU - Oliveira, R. A.P.

AU - Ortolani, S.

AU - Pérez-Villegas, A.

AU - Barbuy, B.

AU - Dias, B.

AU - Bica, E.

AU - Nardiello, D.

PY - 2019/4/21

Y1 - 2019/4/21

N2 - HP 1 is an α-enhanced and moderately metal-poor bulge globular cluster with a blue horizontal branch. These combined characteristics make it a probable relic of the early star formation in the innermost Galactic regions. Here, we present a detailed analysis of a deep near-infrared (NIR) photometry of HP 1 obtained with the NIR GSAOI + GeMS camera at the Gemini-South telescope. J and K S images were collected with an exquisite spatial resolution (FWHM 1/40.1 arcsec), reaching stars at two magnitudes below the MSTO. We combine our GSAOI data with archival F606W-filter HST ACS/WFC images to compute relative proper motions and select bona fide cluster members. Results from statistical isochrone fits in the NIR and optical-NIR colour-magnitude diagrams indicate an age of 12.8 +0.9-0.8 Gyr, confirming that HP 1 is one of the oldest clusters in the Milky Way. The same fits also provide apparent distance moduli in the K S and V filters in very good agreement with the ones from 11 RR Lyrae stars. By subtracting the extinction in each filter, we recover a heliocentric distance of 6.59 +0.17-0.15 kpc. Furthermore, we refine the orbit of HP 1 using this accurate distance and update and accurate radial velocities (from high-resolution spectroscopy) and absolute proper motions (from Gaia DR2), reaching mean perigalactic and apogalactic distances of 1/40.12 and 1/43 kpc, respectively.

AB - HP 1 is an α-enhanced and moderately metal-poor bulge globular cluster with a blue horizontal branch. These combined characteristics make it a probable relic of the early star formation in the innermost Galactic regions. Here, we present a detailed analysis of a deep near-infrared (NIR) photometry of HP 1 obtained with the NIR GSAOI + GeMS camera at the Gemini-South telescope. J and K S images were collected with an exquisite spatial resolution (FWHM 1/40.1 arcsec), reaching stars at two magnitudes below the MSTO. We combine our GSAOI data with archival F606W-filter HST ACS/WFC images to compute relative proper motions and select bona fide cluster members. Results from statistical isochrone fits in the NIR and optical-NIR colour-magnitude diagrams indicate an age of 12.8 +0.9-0.8 Gyr, confirming that HP 1 is one of the oldest clusters in the Milky Way. The same fits also provide apparent distance moduli in the K S and V filters in very good agreement with the ones from 11 RR Lyrae stars. By subtracting the extinction in each filter, we recover a heliocentric distance of 6.59 +0.17-0.15 kpc. Furthermore, we refine the orbit of HP 1 using this accurate distance and update and accurate radial velocities (from high-resolution spectroscopy) and absolute proper motions (from Gaia DR2), reaching mean perigalactic and apogalactic distances of 1/40.12 and 1/43 kpc, respectively.

KW - Galaxy: bulge

KW - globular clusters: individual: HP 1

KW - infrared: stars

KW - instrumentation: adaptive optics

UR - http://www.scopus.com/inward/record.url?scp=85062278147&partnerID=8YFLogxK

U2 - 10.1093/mnras/stz003

DO - 10.1093/mnras/stz003

M3 - Article

AN - SCOPUS:85062278147

VL - 484

SP - 5530

EP - 5550

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 4

ER -

Kerber LO, Libralato M, Souza SO, Oliveira RAP, Ortolani S, Pérez-Villegas A y otros. A deep view of a fossil relic in the Galactic bulge: The Globular Cluster HP 1. Monthly Notices of the Royal Astronomical Society. 2019 abr 21;484(4):5530-5550. https://doi.org/10.1093/mnras/stz003