Near-infrared spectroscopy of Charon: Possible evidence for cryovolcanism on kuiper belt objects

Jason C. Cook, Steven Desch, Ted L. Roush, Chadwick A. Trujillo, T. R. Geballe

Research output: Contribution to journalArticle

90 Citations (Scopus)

Abstract

We present the first reported adaptive optics spectra of Charon in the H and K bands, which examine the anti-Pluto and sub-Pluto hemispheres. The ice temperature is estimated at 40-50 K, based on the 1.65 μm feature of crystalline water ice. We obtain the most accurate profiles of the 2.21 μm feature and confirm that the feature is due to hydrated ammonia. We attribute hemispheric differences in the feature's profile to different hydration states. We calculate the rate at which crystalline water ice is amorphized by solar UV/visible radiation, finding that at the depths probed by H and K observations (≈350 μm), the e-folding time to amorphize ice is (3-5) × 10 4 yr. This implies Charon's ice crystallized from a melt, or has been heated to ≳90 K, during the last ∼ 105 yr. The extent of the crystalline water ice and the short timescales involved argue that surface renewal is necessary, a conclusion reinforced by the presence of ammonia hydrates. We investigate possible mechanisms for surface renewal and conclude that cryovolcanism is the most likely.

Original languageEnglish (US)
Pages (from-to)1406-1419
Number of pages14
JournalAstrophysical Journal
Volume663
Issue number2 I
DOIs
StatePublished - Jul 10 2007

Fingerprint

Charon
Kuiper belt
infrared spectroscopy
near infrared
ice
Pluto (planet)
Pluto
ammonia
water
profiles
extremely high frequencies
hemispheres
adaptive optics
hydration
hydrates
folding
melt
timescale

Keywords

  • Comets: general
  • Infrared: general
  • Kuiper belt
  • Planets and satellites: individual (Charon)

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Near-infrared spectroscopy of Charon : Possible evidence for cryovolcanism on kuiper belt objects. / Cook, Jason C.; Desch, Steven; Roush, Ted L.; Trujillo, Chadwick A.; Geballe, T. R.

In: Astrophysical Journal, Vol. 663, No. 2 I, 10.07.2007, p. 1406-1419.

Research output: Contribution to journalArticle

Cook, Jason C. ; Desch, Steven ; Roush, Ted L. ; Trujillo, Chadwick A. ; Geballe, T. R. / Near-infrared spectroscopy of Charon : Possible evidence for cryovolcanism on kuiper belt objects. In: Astrophysical Journal. 2007 ; Vol. 663, No. 2 I. pp. 1406-1419.
@article{fe595446327f474aba916390dd47c5ec,
title = "Near-infrared spectroscopy of Charon: Possible evidence for cryovolcanism on kuiper belt objects",
abstract = "We present the first reported adaptive optics spectra of Charon in the H and K bands, which examine the anti-Pluto and sub-Pluto hemispheres. The ice temperature is estimated at 40-50 K, based on the 1.65 μm feature of crystalline water ice. We obtain the most accurate profiles of the 2.21 μm feature and confirm that the feature is due to hydrated ammonia. We attribute hemispheric differences in the feature's profile to different hydration states. We calculate the rate at which crystalline water ice is amorphized by solar UV/visible radiation, finding that at the depths probed by H and K observations (≈350 μm), the e-folding time to amorphize ice is (3-5) × 10 4 yr. This implies Charon's ice crystallized from a melt, or has been heated to ≳90 K, during the last ∼ 105 yr. The extent of the crystalline water ice and the short timescales involved argue that surface renewal is necessary, a conclusion reinforced by the presence of ammonia hydrates. We investigate possible mechanisms for surface renewal and conclude that cryovolcanism is the most likely.",
keywords = "Comets: general, Infrared: general, Kuiper belt, Planets and satellites: individual (Charon)",
author = "Cook, {Jason C.} and Steven Desch and Roush, {Ted L.} and Trujillo, {Chadwick A.} and Geballe, {T. R.}",
year = "2007",
month = "7",
day = "10",
doi = "10.1086/518222",
language = "English (US)",
volume = "663",
pages = "1406--1419",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2 I",

}

TY - JOUR

T1 - Near-infrared spectroscopy of Charon

T2 - Possible evidence for cryovolcanism on kuiper belt objects

AU - Cook, Jason C.

AU - Desch, Steven

AU - Roush, Ted L.

AU - Trujillo, Chadwick A.

AU - Geballe, T. R.

PY - 2007/7/10

Y1 - 2007/7/10

N2 - We present the first reported adaptive optics spectra of Charon in the H and K bands, which examine the anti-Pluto and sub-Pluto hemispheres. The ice temperature is estimated at 40-50 K, based on the 1.65 μm feature of crystalline water ice. We obtain the most accurate profiles of the 2.21 μm feature and confirm that the feature is due to hydrated ammonia. We attribute hemispheric differences in the feature's profile to different hydration states. We calculate the rate at which crystalline water ice is amorphized by solar UV/visible radiation, finding that at the depths probed by H and K observations (≈350 μm), the e-folding time to amorphize ice is (3-5) × 10 4 yr. This implies Charon's ice crystallized from a melt, or has been heated to ≳90 K, during the last ∼ 105 yr. The extent of the crystalline water ice and the short timescales involved argue that surface renewal is necessary, a conclusion reinforced by the presence of ammonia hydrates. We investigate possible mechanisms for surface renewal and conclude that cryovolcanism is the most likely.

AB - We present the first reported adaptive optics spectra of Charon in the H and K bands, which examine the anti-Pluto and sub-Pluto hemispheres. The ice temperature is estimated at 40-50 K, based on the 1.65 μm feature of crystalline water ice. We obtain the most accurate profiles of the 2.21 μm feature and confirm that the feature is due to hydrated ammonia. We attribute hemispheric differences in the feature's profile to different hydration states. We calculate the rate at which crystalline water ice is amorphized by solar UV/visible radiation, finding that at the depths probed by H and K observations (≈350 μm), the e-folding time to amorphize ice is (3-5) × 10 4 yr. This implies Charon's ice crystallized from a melt, or has been heated to ≳90 K, during the last ∼ 105 yr. The extent of the crystalline water ice and the short timescales involved argue that surface renewal is necessary, a conclusion reinforced by the presence of ammonia hydrates. We investigate possible mechanisms for surface renewal and conclude that cryovolcanism is the most likely.

KW - Comets: general

KW - Infrared: general

KW - Kuiper belt

KW - Planets and satellites: individual (Charon)

UR - http://www.scopus.com/inward/record.url?scp=34547396406&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34547396406&partnerID=8YFLogxK

U2 - 10.1086/518222

DO - 10.1086/518222

M3 - Article

AN - SCOPUS:34547396406

VL - 663

SP - 1406

EP - 1419

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2 I

ER -