摘要
Infrared(IR)spectral energy distribution(SED)is the major tracer of protoplanetary disks.It was recently proposed to use the near-to-mid IR(or K-24)SED slopeαdefined between 2 and 24μm as a potential quantitative tracer of disk age.We critically examine the viability of this idea and confront it with additional statistics of IR luminosities and SED shapes.We point out that,because the statistical properties of most of the complicated physical factors involved in disk evolution are still poorly understood in a quantitative sense,the only viable way is to assume them to be random so that an idealized“average disk”can be defined,which allows theαhistogram to trace its age.We confirm that the statistics of the zeroth order(luminosity),first order(slopeα),and second order characteristics(concavity)of the observed K-24 SEDs indeed carry useful information upon the evolutionary processes of the“average disk”.We also stress that intrinsic diversities in K-24 SED shapes and luminosities are always large at the level of individual stars so that the application of the evolutionary path of the“average disk”to individual stars must be done with care.The data of most curves in plots are provided on GitHub(Disk-age package https://github.com/starage/disk-age/).
作者
Mingchao Liu
Jinhua He
Zhen Guo
Jixing Ge
Yuping Tang
刘明超;何金华;葛继兴;唐雨平(Yunnan Observatories,Chinese Academy of Sciences,Kunming 650216,China;Chinese Academy of Sciences South America Center for Astronomy,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China;Departamento de Astronomía,Universidad de Chile,Las Condes,7591245 Santiago,Chile;Xinjiang Astronomical Observatory,Chinese Academy of Sciences,Urumqi 830011,China;Xinjiang Key Laboratory of Radio Astrophysics,Urumqi 830011,China;Shanghai Key Lab for Astrophysics,Shanghai Normal University,Shanghai 200234,China)
基金
supported by the Natural Science Foundation of Yunnan Province(No.202201 BC070003)
supported by the ANID FONDECYT Postdoctoral program No.3220029
support by ANID,—Millennium Science Initiative Program—NCN19_171
sponsored(in part)by the Chinese Academy of Sciences(CAS)
the CAS South America Center for Astronomy(CASSACA)in Santiago,Chile.
