The infra-red dual imaging and spectrograph for SPHERE: design and performance

Dohlen, Kjetil; Langlois, M.; Saïsse, M.; Hill, L.; Origné, A.; Jacquet, Marc; Fabron, Christophe; Blanc, Jean-Claude; Llored, M.; Carle, M.; Moutou, C.; Vigan, A.; Boccaletti, A.; Carbillet, Marcel; Mouillet, D.; Beuzit, Jean-Luc

doi:10.1117/12.789786

Cited by 194 publications

(96 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The observations were obtained through the Guaranteed Time program. HD 169142 was observed in the J-band filter (l = 1.258 0 , Δλ=0.197 μm) using the polarimetric imaging mode of the infrared dual-band imager and spectrograph (IRDIS; Dohlen et al 2008;Langlois et al 2014), with a plate scale of 12.25 mas pixel -1 (Maire et al 2016) and a 145 mas diameter coronagraphic focal mask (N_ALC_YJ_S, inner working angle (IWA) of 0 08; Boccaletti et al 2008). HD 169142 was observed for ∼53 minutes on-source under moderate AO conditions (seeing of 0 9).…”

Section: Observations and Data Reductionmentioning

confidence: 99%

The Circumstellar Disk HD 169142: Gas, Dust, and Planets Acting in Concert?*

Pohl

Benisty

Pinilla

et al. 2017

ApJ

View full text Add to dashboard Cite

HD 169142 is an excellent target for investigating signs of planet-disk interaction due to previous evidence of gap structures. We perform J-band (∼1.2 μm) polarized intensity imaging of HD 169142 with VLT/SPHERE. We observe polarized scattered light down to 0 16 (∼19 au) and find an inner gap with a significantly reduced scattered-light flux. We confirm the previously detected double-ring structure peaking at 0 18 (∼21 au) and 0 56 (∼66 au) and marginally detect a faint third gap at 0 70-0 73 (∼82-85 au). We explore dust evolution models in a disk perturbed by two giant planets, as well as models with a parameterized dust size distribution. The dust evolution model is able to reproduce the ring locations and gap widths in polarized intensity but fails to reproduce their depths. However, it gives a good match with the ALMA dust continuum image at 1.3 mm. Models with a parameterized dust size distribution better reproduce the gap depth in scattered light, suggesting that dust filtration at the outer edges of the gaps is less effective. The pileup of millimeter grains in a dust trap and the continuous distribution of small grains throughout the gap likely require more efficient dust fragmentation and dust diffusion in the dust trap. Alternatively, turbulence or charging effects might lead to a reservoir of small grains at the surface layer that is not affected by the dust growth and fragmentation cycle dominating the dense disk midplane. The exploration of models shows that extracting planet properties such as mass from observed gap profiles is highly degenerate.

show abstract

Section: Observations and Data Reductionmentioning

confidence: 99%

The Circumstellar Disk HD 169142: Gas, Dust, and Planets Acting in Concert?*

Pohl

Benisty

Pinilla

et al. 2017

ApJ

View full text Add to dashboard Cite

show abstract

“…Data were obtained simultaneously using the InfraRed Dual-beam Imager and Spectrograph (IRDIS; Dohlen et al 2008) and the infrared Integral Field Spectrograph (IFS; Claudi et al 2008). We also reanalyze the HARPS (Mayor et al 2003) and CORALIE (Queloz et al 2000) spectra, and the EulerCam (Lendl et al 2012) r-band light curves of WASP-20 were published in A15.…”

Section: Observations and Data Reductionmentioning

confidence: 99%

Wasp-20 Is a Close Visual Binary With a Transiting Hot Jupiter

Evans

Southworth

Smalley

2016

ApJL

View full text Add to dashboard Cite

We announce the discovery that WASP-20 is a binary stellar system, consisting of two components separated by 0.2578±0 0007 on the sky, with a flux ratio of 0.4639±0.0015 in the K-band. It has previously been assumed that the system consists of a single F9 V star, with photometric and radial velocity signals consistent with a lowdensity transiting giant planet. With a projected separation of approximately 60 au between the two components, the detected planetary signals almost certainly originate from the brighter of the two stars. We reanalyze previous observations allowing for two scenarios, "planet transits A" and "planet transits B," finding that both cases remain consistent with a transiting gas giant. However, we rule out the "planet transits B" scenario because the observed transit duration requires star B to be significantly evolved, and therefore have an age much greater than star A. We outline further observations that can be used to confirm this finding. Our preferred "planet transits A" scenario results in the measured mass and radius of the planet increasing by 4σ and 1σ, respectively.

show abstract

“…We used the IRDIS subsystem 16 in dual-band imaging. 17 The IRDIS imager splits the incoming light in two channels where the dual-band filters H2 and H3 were inserted ( H2 = 1.588µm, H2 = 53.1nm, H3 = 1.667µm, H3 = 55.6nm).…”

Section: Measurementsmentioning

confidence: 99%

Speckle lifetime in XAO coronagraphic images: temporal evolution of SPHERE coronagraphic images

Milli¹,

Banas²,

Mouillet

et al. 2016

Adaptive Optics Systems V

View full text Add to dashboard Cite

The major source of noise in high-contrast imaging is the presence of slowly evolving speckles that do not average with time. The temporal stability of the point-spread-function (PSF) is therefore critical to reach a high contrast with extreme adaptive optics (XAO) instruments. Understanding on which timescales the PSF evolves and what are the critical parameters driving the speckle variability allow to design an optimal observing strategy and data reduction technique to calibrate instrumental aberrations and reveal faint astrophysical sources. We have obtained a series of 52 min, AO-corrected, coronagraphically occulted, high-cadence (1.6Hz), H-band images of the star HR 3484 with the SPHERE (Spectro-Polarimeter High-contrast Exoplanet REsearch 1 ) instrument on the VLT. This is a unique data set from an XAO instrument to study its stability on timescales as short as one second and as long as several tens of minutes. We find di↵erent temporal regimes of decorrelation. We show that residuals from the atmospheric turbulence induce a fast, partial decorrelation of the PSF over a few seconds, before a transition to a regime with a linear decorrelation with time, at a rate of several tens parts per million per second (ppm/s). We analyze the spatial dependence of this decorrelation within the well-corrected radius of the adaptive optics system and show that the linear decorrelation is faster at short separations. Last, we investigate the influence of the distance to the meridian on the decorrelation.

show abstract

The infra-red dual imaging and spectrograph for SPHERE: design and performance

Cited by 194 publications

References 11 publications

The Circumstellar Disk HD 169142: Gas, Dust, and Planets Acting in Concert?*

The Circumstellar Disk HD 169142: Gas, Dust, and Planets Acting in Concert?*

Wasp-20 Is a Close Visual Binary With a Transiting Hot Jupiter

Speckle lifetime in XAO coronagraphic images: temporal evolution of SPHERE coronagraphic images

Contact Info

Product

Resources

About