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First light of the VLT planet finder SPHERE II. The physical properties and the architecture of the young systems PZ Telescopii and HD 1160 revisited

Maire, A.-L. and Mawet, D. (2016) First light of the VLT planet finder SPHERE II. The physical properties and the architecture of the young systems PZ Telescopii and HD 1160 revisited. Astronomy and Astrophysics, 587 . Art. No. A56. ISSN 0004-6361. http://resolver.caltech.edu/CaltechAUTHORS:20160503-095241937

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Abstract

Context. The young systemsPZ Tel and HD 1160, hosting known low-mass companions, were observed during the commissioning of the new planet finder of the Very Large Telescope (VLT) SPHERE with several imaging and spectroscopic modes. Aims. We aim to refine the physical properties and architecture of both systems. Methods. We use SPHERE commissioning data and dedicated Rapid Eye Mount (REM) observations, as well as literature and unpublished data from VLT/SINFONI, VLT/NaCo, Gemini/NICI, and Keck/NIRC2. Results. We derive new photometry and confirm the short-term (P = 0.94 d) photometric variability of the star PZ Tel A with values of 0.14 and 0.06 mag at optical and near-infrared wavelengths, respectively. We note from the comparison to literature data spanning 38 yr that the star also exhibits a long-term variability trend with a brightening of ~0.25 mag. The 0.63−3.8 μm spectral energy distribution of PZ Tel B (separation ~25 AU) allows us to revise its physical characteristics: spectral type M7 ± 1, T_(eff) = 2700 ± 100 K, log(g) < 4.5 dex, luminosity log(L/L_⊙) = −2.51 ± 0.10 dex, and mass 38−72 M_J from “hot-start” evolutionary models combining the ranges of the temperature and luminosity estimates. The 1−3.8 μm SED of HD 1160 B (~85 au) suggests a massive brown dwarf or a low-mass star with spectral type M6.0^(+1.0)_(-0.5), T_(eff) = 3000 ± 100 K, subsolar metallicity [M/H] = −0.5−0.0 dex, luminosity log(L/L_⊙) = −2.81 ± 0.10 dex, and mass 39−166 M_J. The physical properties derived for HD 1160 C (~560 au) from K_sL′-band photometry are consistent with the discovery study. The orbital study of PZ Tel B confirms its deceleration and the high eccentricity of its orbit (e > 0.66). For eccentricities below 0.9, the inclination, longitude of the ascending node, and time of periastron passage are well constrained. In particular, both star and companion inclinations are compatible with a system seen edge-on. Based on “hot-start” evolutionary models, we reject other brown dwarf candidates outside 0.25" for both systems, and giant planet companions outside 0.5" that are more massive than 3 MJ for the PZ Tel system. We also show that K1−K2 color can be used along with YJH low-resolution spectra to identify young L-type companions, provided high photometric accuracy (≤0.05 mag) is achieved. Conclusions. SPHERE opens new horizons in the study of young brown dwarfs and giant exoplanets using direct imaging thanks to high-contrast imaging capabilities at optical (0.5−0.9 μm) and near-infrared (0.95−2.3 μm) wavelengths, as well as high signal-to-noise spectroscopy in the near-infrared domain (0.95−2.3 μm) from low resolutions (R ~ 30−50) to medium resolutions (R ~ 350).


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1051/0004-6361/201526594DOIArticle
http://www.aanda.org/articles/aa/abs/2016/03/aa26594-15/aa26594-15.htmlPublisherArticle
ORCID:
AuthorORCID
Mawet, D.0000-0002-8895-4735
Additional Information:© ESO 2016. Received 25 May 2015. Accepted 13 October 2015. We thank the anonymous referee for a constructive report on the manuscript and Daniel Rouan for helpful suggestions. The authors are grateful to the Consortium and the ESO Paranal Staff for making SPHERE a reality. The authors warmly thank Andrea Bellini and Jay Anderson for kindly providing the catalog positions of the stars in the 47 Tuc field before their publication. We are also grateful to ESO for releasing the commissioning data for publication. A.-L.M., S.M., D.M., R.G., S.D., R.U.C., and A.Z. acknowledge support from the “Progetti Premiali” funding scheme of the Italian Ministry of Education, University, and Research. A.-L.M. thanks the MPIA for support during the last stages of this work. A.V., M.B., G.C., and D.M. acknowledge financial support from the French National Research Agency (ANR) through the GUEPARD project grant ANR10-BLANC0504-01, the CNRS-D2P PICS grant, and the Programmes Nationaux de Planétologie et de Physique Stellaire (PNP & PNPS). D.E. acknowledges the financial support of the Swiss National Science Fundation (SNSF) through the National Centre for Competence in Research “PlanetS”. A.Z. acknowledges support from the Millennium Science Initiative (Chilean Ministry of Economy), through grant “Nucleus RC130007”. This research has benefitted from the SpeX Prism Spectral Libraries, maintained by Adam Burgasser at http://pono.ucsd.edu/~adam/browndwarfs/spexprism. This research made use of the SIMBAD data base, as well as the VizieR catalog access tool, both operated at the CDS, Strasbourg, France. The original description of the VizieR service was published in Ochsenbein et al. (2000, A&AS, 143, 23). SPHERE is an instrument designed and built by a consortium consisting of IPAG (Grenoble, France), MPIA (Heidelberg, Germany), LAM (Marseille, France), LESIA (Paris, France), Laboratoire Lagrange (Nice, France), INAF − Osservatorio di Padova (Italy), Observatoire de Genève (Switzerland), ETH Zurich (Switzerland), NOVA (Netherlands), ONERA (France), and ASTRON (Netherlands), in collaboration with ESO. SPHERE was funded by ESO, with additional contributions from the CNRS (France), MPIA (Germany), INAF (Italy), FINES (Switzerland), and NOVA (Netherlands). SPHERE also received funding from the European Commission Sixth and Seventh Framework Programs as part of the Optical Infrared Coordination Network for Astronomy (OPTICON) under grant number RII3-Ct-2004-001566 for FP6 (2004−2008), grant number 226604 for FP7 (2009−2012), and grant number 312430 for FP7 (2013−2016).
Funders:
Funding AgencyGrant Number
Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR)UNSPECIFIED
Max Planck Institute for Astronomy (MPIA)UNSPECIFIED
Agence Nationale de la Recherche (ANR)ANR10-BLANC0504-01
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
Programmes Nationaux de Planétologie et de Physique Stellaire (PNP & PNPS)UNSPECIFIED
Swiss National Science Fundation (SNSF)UNSPECIFIED
Millennium Science Initiative (Chile Ministry of Economy)RC130007
European Southern Observatory (ESO)UNSPECIFIED
Istituto Nazionale di Astrofisica (INAF)UNSPECIFIED
FINES (Switzerland)UNSPECIFIED
Nederlandse Onderzoekschool voor de Astronomie (NOVA)UNSPECIFIED
European Commission Sixth and Seventh Framework ProgrammesRII3-Ct-2004-001566 (OPTICON)
European Research Council (ERC)226604
Subject Keywords:brown dwarfs – stars: individual: PZ Telescopii – stars: individual: HD 1160 – techniques: high angular resolution – techniques: image processing – techniques: spectroscopic
Record Number:CaltechAUTHORS:20160503-095241937
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20160503-095241937
Official Citation:First light of the VLT planet finder SPHERE - II. The physical properties and the architecture of the young systems PZ Telescopii and HD 1160 revisited A.-L. Maire, M. Bonnefoy, C. Ginski, A. Vigan, S. Messina, D. Mesa, R. Galicher, R. Gratton, S. Desidera, T. G. Kopytova, M. Millward, C. Thalmann, R. U. Claudi, D. Ehrenreich, A. Zurlo, G. Chauvin, J. Antichi, A. Baruffolo, A. Bazzon, J.-L. Beuzit, P. Blanchard, A. Boccaletti, J. de Boer, M. Carle, E. Cascone, A. Costille, V. De Caprio, A. Delboulbé, K. Dohlen, C. Dominik, M. Feldt, T. Fusco, J. H. Girard, E. Giro, D. Gisler, L. Gluck, C. Gry, T. Henning, N. Hubin, E. Hugot, M. Jaquet, M. Kasper, A.-M. Lagrange, M. Langlois, D. Le Mignant, M. Llored, F. Madec, P. Martinez, D. Mawet, J. Milli, O. Möller-Nilsson, D. Mouillet, T. Moulin, C. Moutou, A. Origné, A. Pavlov, C. Petit, J. Pragt, P. Puget, J. Ramos, S. Rochat, R. Roelfsema, B. Salasnich, J.-F. Sauvage, H. M. Schmid, M. Turatto, S. Udry, F. Vakili, Z. Wahhaj, L. Weber and F. Wildi A&A, 587 (2016) A56 DOI: http://dx.doi.org/10.1051/0004-6361/201526594
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ID Code:66614
Collection:CaltechAUTHORS
Deposited By: Ruth Sustaita
Deposited On:03 May 2016 18:11
Last Modified:03 May 2016 18:11

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