Main final dvi
Yüklə 354,89 Kb. Pdf görüntüsü
|
- Bu səhifədəki naviqasiya:
- Period [days]
- ln L 1% FAP P 1 = 215 days 11.19 days RV - HARPS pre-2016
- ln L 1% FAP P 1 11.3 days 38 days RV - HARPS PRD
- ln L 1% FAP P 1 103 days LCOGT V 39.1 days c
- LCOGT B 39.1 days d Extended Data Figure 3: Signal searches on the photometry
signals (e.g. activity) in the range of a few hundred days will inject severe interference in the period domain of interest, and explains why this set is where the Doppler signal at 11.2 days is detected with less confidence (see Extended Data Figure 2). 20
2 5 10 20 50 100 300 1000
Period [days] 0 10 20 ∆
1% FAP P 1 = 11.2 days RV - UVES a 2 5 10 20 50 100 300
1000 Period [days] 0 10 20 ∆
1% FAP P 1 = 215 days ~ 11.19 days RV - HARPS pre-2016 b 2 5 10 20 50 100 300
1000 Period [days] 0 10 20 ∆
1% FAP P 1 ~ 11.3 days ~ 38 days RV - HARPS PRD c Extended Data Figure 2: Signal searches on independent radial velocity datasets. Likelihood- ratio periodograms searches on the RV measurements of the UVES (panel a), HARPS pre-2016 (panel b) and HARPS PRD (panel c) subsets. The periodogram with all three sets combined is shown in Figure 1 of the main manuscript. Black and red lines represent the searches for A first and a second signal respectively.
Here we present likelihood-ratio periodogram searches for signals in the three Doppler time-series separately (PRD, HARPS pre-2016, and UVES). They are analyzed in the same way as the activ- ity indices to enable direct visual comparison. They differ from the ones presented in the main manuscript in the sense that they do not include MA terms and the signals are modelled as pure sinusoids to mirror the analysis of the other time-series as close as possible. The resulting peri- odograms are shown in Extended data Figure 2. A signal at 11.2 days was close to detection using UVES data-only. However, let us note that the signal was not clearly detectable using the Doppler measurements as provided by the UVES survey, 45 and it only became obvious when new Doppler measurements were re-derived using up-to-date Iodine codes (Section 2.1). The signal is weaker in the HARPS pre-2016 dataset, but it still appears as a possible second signal after modeling the longer term variability with a Keplerian at 200 days. Sub-sets of the HARPS pre-2106 data taken in consecutive nights (eg. HARPS high-cadence runs) also show strong evidence of the same sig- nal. However splitting the data in subsets adds substantial complexity to the analysis and the results become quite sensitive to subjective choices (how to split the data and how to weight each subset). The combination UVES with all the HARPS pre-2016 (Figure 1, panel a) already produced a FAP of ∼1%, but a dedicated campaign was deemed necessary given the caveats with the sampling and activity related variability. The HARPS PRD campaign unambiguously identifies a signal with the 21
same ∼ 11.2 days period. As discussed earlier, the combination of all the data results in a very high significance, which implies that the period, but also the amplitude and phase are consistent in all three sets. 22
2 5 10 20 50 100 Period [days] 0 20 40 60 80 100 ∆
1% FAP P 1 ~ 84 days ASH2 SII P 2 ~ 39.1 days 2.37 days a 2 5 10 20 50 100 Period [days] 0 10 20 30 40 ∆ ln L 1% FAP P 1 ~ 84 days ASH2 H- α
b 2 5 10 20 50 100 Period [days] 0 10 20 30 40 ∆ ln L 1% FAP P 1 ~ 103 days LCOGT V ~ 39.1 days c 2 5 10 20 50 100 Period [days] 0 10 20 30 40 ∆ ln L 1% FAP P 1 ~ 110 days LCOGT B ~ 39.1 days d Extended Data Figure 3: Signal searches on the photometry. Likelihood-ratio periodograms searches for signals in each photometric ASH2 photometric band (panels a and b) and LCOGT bands (panels c and d). The two sinusoid fit to the ASH2 SII series ( P 1 = 84 days, P 2 = 39.1 days), is used later to construct the FF ′ model to test for correlations of the photometry with the RV data. Black, red and blue lines represent the search for a first, second and third signals respectively. 5.3 Photometry. Signals and calculation of the FF ′
The nightly average of the four photometric series was computed after removing the measurements clearly contaminated by flares (see Figure 3 in main manuscript). This produces 43 LCOGT epochs in the B and V bands (80 nights), and 66 ASH2 epochs in both SII and H α bands (100 nights cov- ered). The precision of each epoch was estimated using the internal dispersion within a given night. All four photometric series show evidence of a long period signal compatible with a photometric cycle at 83-d (likely rotation) reported before. 3 See periodograms in Extended data Figure 3. In the presence of spots, it has been proposed that spurious variability should be linearly corre- lated with the value of the normalized flux of the star F , the derivative of the flux F ′ , and the product of FF ′ 62 in what is sometimes called the FF ′ model. To include the photometry in the analysis of the Doppler data, we used the best model fit of the highest quality light curve (AHS2 SII, has the lowest post-fit scatter) to estimate F , F ′
F F ′ at the instant of each PRD observation. The relation of F , F
′ , and
F F ′ to the Doppler variability is investigated later in the Bayesian analysis of the 23 Yüklə 354,89 Kb. Dostları ilə paylaş:
|