The EXPRES Stellar Signals Project II. State of the Field in Disentangling Photospheric Velocities

• Type: Article in International Scientific Journal
• Date: 2022

Authors

Zhao, LL (Author) Other; Fischer, DA (Author) Other; Ford, EB (Author) Other; Wise, A (Author) Other; Cretignier, M (Author) Other; Aigrain, S (Author) Other; Barragan, O (Author) Other; Bedell, M (Author) Other; Buchhave, LA (Author) Other; Camacho, JD (Author) Other; Cegla, HM (Author) Other; Cisewski Kehe, J (Author) Other; Cameron, AC (Author) Other; de Beurs, ZL (Author) Other; Dodson Robinson, S (Author) Other; Dumusque, X (Author) Other; Faria, JP (Author) Other; Gilbertson, C (Author) Other; Haley, C (Author) Other; Harrell, J (Author) Other; Hogg, DW (Author) Other; Holzer, P (Author) Other; John, AA (Author) Other; Klein, B (Author) Other; Lafarga, M (Author) Other; Lienhard, F (Author) Other; Maguire Rajpaul, V (Author) Other; Mortier, A (Author) Other; Nicholson, B (Author) Other; Palumbo, ML (Author) Other; Delgado, VR (Author) Other; Shallue, CJ (Author) Other; Vanderburg, A (Author) Other; viana, ptp (Author) FCUP; Zhao, JL (Author) Other; Zicher, N (Author) Other; Cabot, SHC (Author) Other; Henry, GW (Author) Other; Roettenbacher, RM (Author) Other; Brewer, JM (Author) Other; Llama, J (Author) Other; Petersburg, RR (Author) Other; Szymkowiak, AE (Author) Other

Journal

Title: Astronomical Journal

Vol. 163

Final page: 171

ISSN: 0004-6256

Publisher: American Astronomical Society

Indexing

ISI Web of Knowledge - 23 Citations

Scopus - 25 Citations

Other information

Authenticus ID: P-00W-9Z4

DOI: 10.3847/1538-3881/ac5176

Abstract (EN): Measured spectral shifts due to intrinsic stellar variability (e.g., pulsations, granulation) and activity (e.g., spots, plages) are the largest source of error for extreme-precision radial-velocity (EPRV) exoplanet detection. Several methods are designed to disentangle stellar signals from true center-of-mass shifts due to planets. The Extreme-precision Spectrograph (EXPRES) Stellar Signals Project (ESSP) presents a self-consistent comparison of 22 different methods tested on the same extreme-precision spectroscopic data from EXPRES. Methods derived new activity indicators, constructed models for mapping an indicator to the needed radial-velocity (RV) correction, or separated out shape- and shift-driven RV components. Since no ground truth is known when using real data, relative method performance is assessed using the total and nightly scatter of returned RVs and agreement between the results of different methods. Nearly all submitted methods return a lower RV rms than classic linear decorrelation, but no method is yet consistently reducing the RV rms to sub-meter-per-second levels. There is a concerning lack of agreement between the RVs returned by different methods. These results suggest that continued progress in this field necessitates increased interpretability of methods, high-cadence data to capture stellar signals at all timescales, and continued tests like the ESSP using consistent data sets with more advanced metrics for method performance. Future comparisons should make use of various well-characterized data sets-such as solar data or data with known injected planetary and/or stellar signals-to better understand method performance and whether planetary signals are preserved.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 34