High Altitude Observatory / NCAR, PO Box 3000, Boulder, CO 80307, USA; National Astronomical Observatory, Chinese Academy of Sciences, Datun Road A20, Chaoyang District, Beijing, 100012 China
Department of Astrophysical Sciences and PACM, Princeton University, Peyton Hall, Ivy Lane, Princeton, NJ 08544, USA
High Altitude Observatory / NCAR, PO Box 3000, Boulder, CO 80307, USA