J/ApJ/785/33 High quality Spitzer/MIPS obs. of F4-K2 stars (Sierchio+, 2014) ================================================================================ The decay of debris disks around solar-type stars. Sierchio J.M., Rieke G.H., Su K.Y.L., Gaspar A. =2014ApJ...785...33S (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Photometry, infrared ; Abundances, [Fe/H] ; Stars, ages Keywords: circumstellar matter; infrared: planetary systems Abstract: We present a Spitzer MIPS study of the decay of debris disk excesses at 24 and 70{mu}m for 255 stars of types F4-K2. We have used multiple tests, including consistency between chromospheric and X-ray activity and placement on the H-R diagram, to assign accurate stellar ages. Within this spectral type range, at 24{mu}m, 13.6%+/-2.8% of the stars younger than 1 Gyr have excesses at the 3{sigma} level or more, whereas none of the older stars do, confirming previous work. At 70{mu}m, 22.5%+/-3.6% of the younger stars have excesses at >=3{sigma} significance, whereas only 4.7_-2.2_^+3.7^% of the older stars do. To characterize the far-infrared behavior of debris disks more robustly, we doubled the sample by including stars from the DEBRIS and DUNES surveys. For the F4-K4 stars in this combined sample, there is only a weak (statistically not significant) trend in the incidence of far-infrared excess with spectral type (detected fractions of 21.9_-4.3_^+4.8^%, late F; 16.5_-3.3_^+3.9^%, G; and 16.9_-5.0_^+6.3^%, early K). Taking this spectral type range together, there is a significant decline between 3 and 4.5 Gyr in the incidence of excesses, with fractional luminosities just under 10^-5^. There is an indication that the timescale for decay of infrared excesses varies roughly inversely with the fractional luminosity. This behavior is consistent with theoretical expectations for passive evolution. However, more excesses are detected around the oldest stars than are expected from passive evolution, suggesting that there is late-phase dynamical activity around these stars. Description: We used specific criteria to draw samples of stars from the entire Spitzer Debris Disk Database (see section 2.1.1). V magnitudes were taken from Hipparcos and transformed to Johnson V. All stars were also required to have observations on the Two Micron All Sky Survey (2MASS) Ks system. Additional measurements were obtained at SAAO on the 0.75m telescope using the MarkII Infrared Photometer (transformed as described by Koen et al. 2007MNRAS.380.1433K), and at the Steward Observatory 61 in telescope using a NICMOS2-based camera with a 2MASS filter set and a neutral density filter to avoid saturation. These measurements will be described in a forthcoming paper (K. Y. L. Su et al., in preparation). The original programs in which our sample stars were measured are identified in Table 1. A large majority (93%) come from seven Spitzer programs: (1) the MIPS Guaranteed Time Observer (GTO) Sun-like star observations (Trilling+ 2008ApJ...674.1086T); (2) Formation and Evolution of Planetary Systems (FEPS; Meyer+ 2006, J/PASP/118/1690); (3) Completing the Census of Debris Disks (Koerner+ 2010ApJ...710L..26K); (4) potential Space Interferometry Mission/Terrestrial Planet Finder (SIM/TPF) targets (Beichman+ 2006ApJ...652.1674B); (5) an unbiased sample of F-stars (Trilling+ 2008ApJ...674.1086T); and (6) two coordinated programs selecting stars on the basis of indicators of youth (Low+ 2005ApJ...631.1170L; Plavchan+ 2009ApJ...698.1068P). See section 2.1.2. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table2.dat 123 255 Spitzer star sample -------------------------------------------------------------------------------- See also: V/130 : Geneva-Copenhagen Survey of Solar neighbourhood III (Holmberg+, 2009) V/136 : Teff and metallicities for Tycho-2 stars (Ammons+, 2006) IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999) V/89 : Ages, Metallicities, Galactic Orbit of F stars (Marsakov+ 1995) J/ApJ/775/55 : Spitzer IR excesses in A-K stars (Ballering+, 2013) J/A+A/555/A11 : DUNES survey observational results (Eiroa+, 2013) J/ApJ/768/25 : Spitzer & Herschel obs. of debris disks (Gaspar+, 2013) J/ApJ/753/147 : Herschel observations stars in THA (Donaldson+, 2012) J/ApJ/750/98 : 24um observations of AFGKM stars of 3 clusters (Urban+, 2012) J/A+A/541/A40 : Metallicity of solar-type stars (Maldonado+, 2012) J/ApJ/745/147 : Binaries among debris disk stars (Rodriguez+, 2012) J/AZh/88/1217 : Solar-like activity of low-mass stars (Kasova+, 2011) J/MNRAS/416/3108 : Membership of Sco OB2 moving group (Rizzuto+, 2011) J/AZh/88/750 : Stars of galactic sub-structure abundances (Mishenina+, 2011) J/MNRAS/410/190 : Young runaway stars within 3kpc (Tetzlaff+, 2011) J/ApJ/725/875 : Chromospheric activity for CPS stars (Isaacson+, 2010) J/A+A/520/A79 : FGK stars chromospheric activity (Martinez-Arnaiz+, 2010) J/ApJ/705/1226 : Planet-bearing stars in Spitzer (Bryden+, 2009) J/A+A/493/1099 : CaII HK emission in rapidly rotating stars (Schroeder+, 2009) J/ApJ/687/1264 : Age estimation for solar-type dwarfs (Mamajek+, 2008) J/A+A/483/903 : Mount Wilson index for F-K stars (Buccino+, 2008) J/PASP/119/994 : MIPS 24um calibrators (Engelbracht+, 2007) J/AJ/133/2524 : Spectra of young nearby stars (White+, 2007) J/PASP/118/1690 : Spitzer solar-type stars list (Meyer+, 2006) J/MNRAS/372/163 : Activity indices for southern stars (Jenkins+, 2006) J/AJ/132/161 : NStars project: The southern sample. I. (Gray+, 2006) J/A+A/450/735 : Effective temperatures and radii of stars (Masana+, 2006) J/MNRAS/360/1345 : F- and G-type stars in solar neighbourhood (Karatas+, 2005) J/ApJS/159/141 : Spectroscopic properties of cool stars. I. (Valenti+, 2005) J/ApJ/622/1102 : The planet-metallicity correlation. (Fischer+, 2005) J/ApJ/620/1010 : Spitzer 24{mu}m photometry of A dwarfs (Rieke+, 2005) J/other/ARA+A/42.685 : Young stars near the Sun (Zuckerman+, 2004) J/ApJS/152/261 : Chromospheric Ca II emission in nearby stars (Wright+, 2004) J/A+A/417/651 : NEXXUS ROSAT survey of coronal X-ray (Schmitt+, 2004) J/AJ/126/2048 : NStars project: the Northern Sample. I. (Gray+, 2003) J/AJ/125/3311 : JHKL'M photometry of northern bright stars (Kidger+, 2003) J/A+A/365/545 : Remnant disks around MS stars IR flux (Habing+, 2001) J/MNRAS/298/332 : Chromospheric activity-age relation (Rocha-Pinto+ 1998) J/A+AS/131/209 : JHK(L') photometry of giant stars (Alonso+ 1998) J/A+A/329/943 : F + G solar neighbourhood stars new ages (Ng+ 1998) Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 7 A7 --- Name HD identifier or HIP6276 9- 16 A8 --- SpT MK Spectral type from SIMBAD (F4V to K1V) 24- 28 I5 Myr Age [15/10100] Age 30- 47 A18 --- r_Age Reference(s) for Age (1) 49- 53 F5.1 mas Plx [10/168] Parallax from Hipparcos (see I/239) 55- 59 F5.2 [-] [Fe/H] [-0.9/0.4]? Metallicity 61- 64 F4.2 mag Vmag [2.82/8.65] The Johnson V band magnitude 66- 70 F5.3 mag Ksmag [1.28/7.24] The K_s_ band magnitude in 2MASS system 72- 80 A9 --- r_Ksmag Reference(s) for Ksmag (2) 82- 86 I5 --- PID Spitzer PID indentifier 88- 95 I8 --- AOR Spitzer AOR key 97-103 F7.2 mJy F24 [9/2225] Spitzer/MIPS 24um band flux density 105-109 F5.2 mJy e_F24 [0.1/11] Uncertainty in F24 111-117 F7.2 mJy F70 [-9/1776]? Spitzer/MIPS 70um band flux density 119-123 F5.2 mJy e_F70 [1/90]? Uncertainty in F70 -------------------------------------------------------------------------------- Note (1): Reference of Age as follows: 1 = Schroeder et al. 2009, J/A+A/493/1099 2 = Henry et al. 1996, J/AJ/111/439 3 = Wright et al. 2004, J/ApJS/152/261 4 = Rocha-Pinto & Maciel 1998, J/MNRAS/298/332 5 = Isaacson & Fischer 2010, J/ApJ/725/875 6 = X-ray from RASS 7 = White et al. 2007, J/AJ/133/2524 8 = Gray et al. 2006, J/AJ/132/161 9 = Gray et al. 2003, J/AJ/126/2048 10 = Martinez-Arnaiz et al. 2010, J/A+A/520/A79 11 = Kasova & Livshits 2011, J/AZh/88/1217 12 = Jenkins et al. 2006, J/MNRAS/372/163 13 = Zuckerman & Song 2004, J/other/ARA+A/42.685 14 = Montes et al. 2001, J/MNRAS/328/45 15 = logg<4 16 = Duncan et al. 1991, III/159 17 = Buccino & Mauas 2008, J/A+A/483/903 18 = Rizzuto et al. 2011, J/MNRAS/416/3108 19 = Barrado y Navascues 1998A&A...339..831B 20 = Karatas et al. 2005, J/MNRAS/360/1345 21 = Schmitt & Liefke 2004, J/A+A/417/651 22 = Ng & Bertelli 1998, J/A+A/329/943 23 = Mamajek 2009IAUS..258..375M 24 = Mishenina et al. 2011, J/AZh/88/750 Note (2): Reference of K photometry as follows: 1 = 2MASS; 2 = this work; 3 = Carter (1990MNRAS.242....1C) 4 = Glass (1974MNSSA..33...53G) 5 = Bouchet et al. (1991A&AS...91..409B) 6 = Johnson et al. (1966, II/5) 7 = Selby et al. (1988A&AS...74..127S) 8 = Kidger & Martin-Ruiz (2003, J/AJ/125/3311) 9 = Alonso et al. (1998, J/A+AS/131/209) 10 = Aumann & Probst (1991ApJ...368..264A) 11 = Allen & Gallagher (1983MNRAS.203..777A) 12 = UKIRT (1994, http://www.jach.hawaii.edu/UKIRT/astronomy/calib/phot_cal/bright_stds.html) -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Prepared by [AAS], Emmanuelle Perret [CDS] 01-Dec-2016