# A High Contrast Survey for Extrasolar Giant Planets with the Simultaneous Differential Imager (SDI)

http://hdl.handle.net/10150/194542
Title:
A High Contrast Survey for Extrasolar Giant Planets with the Simultaneous Differential Imager (SDI)
Author:
Biller, Beth Alison
Issue Date:
2007
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
We present the results of a survey of 45 young (<250>Myr), close (<50>pc) stars with the Simultaneous Differential Imager (SDI) implemented at the VLT and the MMT for the direct detection of extrasolar planets. Our SDI devices use a double Wollaston prism and a quad filter to take images simultaneously at three wavelengths surrounding the 1.62 um methane absorption bandhead found in the spectrum of cool brown dwarfs and extrasolar giant planets. By performing a difference of adaptive optics corrected images in these filters, speckle noise from the primary star can be significantly attenuated, resulting in photon (and flat-field) noise limited data. In our VLT data, we achieved H band contrasts > 10 mag (5 sigma) at a separation of 0.5" from the primary star on 45% of our targets and H band contrasts of > 9 mag at a separation of 0.5'' on 80% of our targets. With this degree of attenuation, we should be able to image (5 sigma detection) a 7 MJup planet 15 AU from a 70 Myr K1 star at 15 pc or a 7.8 MJup planet at 2 AU from a 12 Myr M star at 10 pc. Using the capabilities of the unique SDI device, we also discovered a methane-rich substellar companion to SCR 1845-6357 (a recently discovered (Hambly et al., 2004) M8.5 star just 3.85 pc from the Sun (Henry et al., 2006) at a separation of 4.5 AU (1.170''+-0.003'' on the sky) and fainter by 3.57$\pm$0.057 mag in the 1.575 um SDI filter.We also present high resolution (~0.1''), very high Strehl ratio (0.97+-0.03) mid-infrared (IR) adaptive optics (AO) images of the AGB star RV Boo utilizing the MMT adaptive secondary AO system. RV Boo was observed at a number of wavelengths over two epochs and appeared slightly extended at all wavelengths. With such high Strehls we can achieve super-resolutions of 0.1'' by deconvolving RV Boo with a point-spread function (PSF) derived from an unresolved star.SDI on ground based telescopes provides significant speckle attenuations down to star-planet contrasts of ~1-3x10^4. To test the classical SDI technique at contrasts of 10^6-9, we implemented a similar multiwavelength differential imaging scheme for the JPL High Contrast Imaging Testbed.
Type:
text; Electronic Dissertation
Keywords:
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Degree Grantor:
University of Arizona
Close, Laird M.
Committee Chair:
Close, Laird M.

DC FieldValue Language
dc.language.isoENen_US
dc.titleA High Contrast Survey for Extrasolar Giant Planets with the Simultaneous Differential Imager (SDI)en_US
dc.creatorBiller, Beth Alisonen_US
dc.contributor.authorBiller, Beth Alisonen_US
dc.date.issued2007en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractWe present the results of a survey of 45 young (<250>Myr), close (<50>pc) stars with the Simultaneous Differential Imager (SDI) implemented at the VLT and the MMT for the direct detection of extrasolar planets. Our SDI devices use a double Wollaston prism and a quad filter to take images simultaneously at three wavelengths surrounding the 1.62 um methane absorption bandhead found in the spectrum of cool brown dwarfs and extrasolar giant planets. By performing a difference of adaptive optics corrected images in these filters, speckle noise from the primary star can be significantly attenuated, resulting in photon (and flat-field) noise limited data. In our VLT data, we achieved H band contrasts > 10 mag (5 sigma) at a separation of 0.5" from the primary star on 45% of our targets and H band contrasts of > 9 mag at a separation of 0.5'' on 80% of our targets. With this degree of attenuation, we should be able to image (5 sigma detection) a 7 MJup planet 15 AU from a 70 Myr K1 star at 15 pc or a 7.8 MJup planet at 2 AU from a 12 Myr M star at 10 pc. Using the capabilities of the unique SDI device, we also discovered a methane-rich substellar companion to SCR 1845-6357 (a recently discovered (Hambly et al., 2004) M8.5 star just 3.85 pc from the Sun (Henry et al., 2006) at a separation of 4.5 AU (1.170''+-0.003'' on the sky) and fainter by 3.57$\pm$0.057 mag in the 1.575 um SDI filter.We also present high resolution (~0.1''), very high Strehl ratio (0.97+-0.03) mid-infrared (IR) adaptive optics (AO) images of the AGB star RV Boo utilizing the MMT adaptive secondary AO system. RV Boo was observed at a number of wavelengths over two epochs and appeared slightly extended at all wavelengths. With such high Strehls we can achieve super-resolutions of 0.1'' by deconvolving RV Boo with a point-spread function (PSF) derived from an unresolved star.SDI on ground based telescopes provides significant speckle attenuations down to star-planet contrasts of ~1-3x10^4. To test the classical SDI technique at contrasts of 10^6-9, we implemented a similar multiwavelength differential imaging scheme for the JPL High Contrast Imaging Testbed.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectExtrasolar Planetsen_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineAstronomyen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairClose, Laird M.en_US
dc.contributor.committeememberMcCarthy, Donen_US
dc.contributor.committeememberBieging, Johnen_US
dc.contributor.committeememberSchneider, Glennen_US
dc.identifier.proquest2314en_US
dc.identifier.oclc659748172en_US