SIMBAD references

2014ApJS..212...27K - Astrophys. J., Suppl. Ser., 212, 27 (2014/June-0)

Spectroscopic coronagraphy for planetary radial velocimetry of exoplanets.

KAWAHARA H., MURAKAMI N., MATSUO T. and KOTANI T.

Abstract (from CDS):

We propose the application of coronagraphic techniques to the spectroscopic direct detection of exoplanets via the Doppler shift of planetary molecular lines. Even for an unresolved close-in planetary system, we show that the combination of a visible nuller and an extreme adaptive optics system can reduce the photon noise of a main star and increase the total signal-to-noise ratio (S/N) of the molecular absorption of the exoplanetary atmosphere: it works as a spectroscopic coronagraph. Assuming a 30 m telescope, we demonstrate the benefit of these high-contrast instruments for nearby close-in planets that mimic 55 Cnc b (0.6λ/D of the angular separation in the K band). We find that the tip-tilt error is the most crucial factor; however, low-order speckles also contribute to the noise. Assuming relatively conservative estimates for future wavefront control techniques, the spectroscopic coronagraph can increase the contrast ∼50-130 times and enable us to obtain ∼3-6 times larger S/N for warm Jupiters and Neptunes at 10 pc than those without it. If the tip-tilt error can be reduced to ≲ 0.3 mas (rms), it gains ∼10-30 times larger S/N and enables us to detect warm super-Earths with an extremely large telescope. This paper demonstrates the concept of spectroscopic coronagraphy for future spectroscopic direct detection. Further studies of the selection of coronagraphs and tip-tilt sensors will extend the range of application of the spectroscopic direct detection beyond the photon collecting area limit.

Abstract Copyright:

Journal keyword(s): methods: observational - planets and satellites: atmospheres - techniques: miscellaneous

Simbad objects: 3

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2019.10.15-02:19:44

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