THE HARPS-TERRA PROJECT. I. DESCRIPTION OF THE ALGORITHMS, PERFORMANCE, AND NEW MEASUREMENTS ON A FEW REMARKABLE STARS OBSERVED BY HARPS

被引:281
作者
Anglada-Escude, Guillem [1 ,2 ]
Butler, R. Paul [1 ]
机构
[1] Carnegie Inst Sci, Dept Terr Magnetism, Washington, DC 20015 USA
[2] Univ Gottingen, Inst Astrophys, D-37077 Gottingen, Germany
关键词
methods: data analysis; planetary systems; stars: individual (Tau Ceti; HD; 85512; Barnard's star; Proxima; Kapteyn's star; GJ676A; Epsilon Eridani; 69830); techniques: radial velocities; LOW MASS STARS; HABITABLE ZONE; EXTRASOLAR PLANETS; EPSILON-ERIDANI; SHORT-PERIOD; SUPER-EARTH; SEARCH; COMPANIONS; JUPITER; DETECTABILITY;
D O I
10.1088/0067-0049/200/2/15
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Doppler spectroscopy has uncovered or confirmed all the known planets orbiting nearby stars. Two main techniques are used to obtain precision Doppler measurements at optical wavelengths. The first approach is the gas cell method, which consists of least-squares matching of the spectrum of iodine imprinted on the spectrum of the star. The second method relies on the construction of a stabilized spectrograph externally calibrated in wavelength. The most precise stabilized spectrometer in operation is the High Accuracy Radial velocity Planet Searcher (HARPS), operated by the European Southern Observatory in La Silla Observatory, Chile. The Doppler measurements obtained with HARPS are typically obtained using the cross-correlation function (CCF) technique. This technique consists of multiplying the stellar spectrum by a weighted binary mask and finding the minimum of the product as a function of the Doppler shift. It is known that CCF is suboptimal in exploiting the Doppler information in the stellar spectrum. Here we describe an algorithm to obtain precision radial velocity measurements using least-squares matching of each observed spectrum to a high signal-to-noise ratio template derived from the same observations. This algorithm is implemented in our software HARPS-TERRA (Template-Enhanced Radial velocity Re-analysis Application). New radial velocity measurements on a representative sample of stars observed by HARPS are used to illustrate the benefits of the proposed method. We show that, compared with CCF, template matching provides a significant improvement in accuracy, especially when applied to M dwarfs.
引用
收藏
页数:19
相关论文
共 49 条
[1]   A PLANETARY SYSTEM AROUND THE NEARBY M DWARF GJ 667C WITH AT LEAST ONE SUPER-EARTH IN ITS HABITABLE ZONE [J].
Anglada-Escude, Guillem ;
Arriagada, Pamela ;
Vogt, Steven S. ;
Rivera, Eugenio J. ;
Butler, R. Paul ;
Crane, Jeffrey D. ;
Shectman, Stephen A. ;
Thompson, Ian B. ;
Minniti, Dante ;
Haghighipour, Nader ;
Carter, Brad D. ;
Tinney, C. G. ;
Wittenmyer, Robert A. ;
Bailey, Jeremy A. ;
O'Toole, Simon J. ;
Jones, Hugh R. A. ;
Jenkins, James S. .
ASTROPHYSICAL JOURNAL LETTERS, 2012, 751 (01)
[2]   ASTROMETRY AND RADIAL VELOCITIES OF THE PLANET HOST M DWARF GJ 317: NEW TRIGONOMETRIC DISTANCE, METALLICITY, AND UPPER LIMIT TO THE MASS OF GJ 317b [J].
Anglada-Escude, Guillem ;
Boss, Alan P. ;
Weinberger, Alycia J. ;
Thompson, Ian B. ;
Butler, R. Paul ;
Vogt, Steven S. ;
Rivera, Eugenio J. .
ASTROPHYSICAL JOURNAL, 2012, 746 (01)
[3]   EPSILON ERIDANI'S PLANETARY DEBRIS DISK: STRUCTURE AND DYNAMICS BASED ON SPITZER AND CALTECH SUBMILLIMETER OBSERVATORY OBSERVATIONS [J].
Backman, D. ;
Marengo, M. ;
Stapelfeldt, K. ;
Su, K. ;
Wilner, D. ;
Dowell, C. D. ;
Watson, D. ;
Stansberry, J. ;
Rieke, G. ;
Megeath, T. ;
Fazio, G. ;
Werner, M. .
ASTROPHYSICAL JOURNAL, 2009, 690 (02) :1522-1538
[4]   ELODIE: A spectrograph for accurate radial velocity measurements [J].
Baranne, A ;
Queloz, D ;
Mayor, M ;
Adrianzyk, G ;
Knispel, G ;
Kohler, D ;
Lacroix, D ;
Meunier, JP ;
Rimbaud, G ;
Vin, A .
ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES, 1996, 119 (02) :373-390
[5]   The extrasolar planet ∈ Eridani b:: Orbit and mass [J].
Benedict, G. Fritz ;
McArthur, Barbara E. ;
Gatewood, George ;
Nelan, Edmund ;
Cochran, William D. ;
Hatzes, Artie ;
Endl, Michael ;
Wittenmyer, Robert ;
Baliunas, Sallie L. ;
Walker, Gordon A. H. ;
Yang, Stephenson ;
Kuerster, Martin ;
Els, Sebastian ;
Paulson, Diane B. .
ASTRONOMICAL JOURNAL, 2006, 132 (05) :2206-2218
[6]   Catalog of nearby exoplanets [J].
Butler, R. P. ;
Wright, J. T. ;
Marcy, G. W. ;
Fischer, D. A. ;
Vogt, S. S. ;
Tinney, C. G. ;
Jones, H. R. A. ;
Carter, B. D. ;
Johnson, J. A. ;
McCarthy, C. ;
Penny, A. J. .
ASTROPHYSICAL JOURNAL, 2006, 646 (01) :505-522
[7]   Attaining Doppler precision of 3 m s(-1) [J].
Butler, RP ;
Marcy, GW ;
Williams, E ;
McCarthy, C ;
Dosanjh, P ;
Vogt, SS .
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC, 1996, 108 (724) :500-509
[8]   A SEARCH FOR SUBSTELLAR COMPANIONS TO SOLAR-TYPE STARS [J].
CAMPBELL, B ;
WALKER, GAH ;
YANG, S .
ASTROPHYSICAL JOURNAL, 1988, 331 (02) :902-921
[9]   The Lick planet search: Detectability and mass thresholds [J].
Cumming, A ;
Marcy, GW ;
Butler, RP .
ASTROPHYSICAL JOURNAL, 1999, 526 (02) :890-915
[10]   Detectability of extrasolar planets in radial velocity surveys [J].
Cumming, A .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2004, 354 (04) :1165-1176