J/ApJ/919/74 Quiescent coronal loops observed with CoMP (Tiwari+, 2021)
A statistical study of propagating MHD kink waves in the quiescent corona.
Tiwari A.K., Morton R.J., McLaughlin J.A.
<Astrophys. J., 919, 74 (2021)>
=2021ApJ...919...74T 2021ApJ...919...74T
ADC_Keywords: Sun
Keywords: Magnetohydrodynamics ; Quiet solar corona ; Solar coronal loops ;
Solar coronal heating ; Quiet sun ; Solar activity
Abstract:
The Coronal Multi-channel Polarimeter (CoMP) has opened up exciting
opportunities to probe transverse MHD waves in the Sun's corona. The
archive of CoMP data is utilized to generate a catalog of quiescent
coronal loops that can be used for studying propagating kink waves.
The catalog contains 120 loops observed between 2012 and 2014. This
catalog is further used to undertake a statistical study of
propagating kink waves in the quiet regions of the solar corona,
investigating phase speeds, loop lengths, footpoint power ratio (a
measure of wave power entering the corona through each footpoint of a
loop) and equilibrium parameter (which provides a measure of the
change in wave amplitude) values. The statistical study enables us to
establish the presence of a relationship between the rate of damping
and the length of the coronal loop, with longer coronal loops
displaying weaker wave damping. We suggest the reason for this
behavior is related to a decreasing average density contrast between
the loop and ambient plasma as loop length increases. The catalog
presented here will provide the community with the foundation for the
further study of propagating kink waves in the quiet solar corona.
Description:
The data are obtained from the Coronal Multi-channel Polarimeter
(CoMP), a coronagraph that observes the off-limb corona between
1.05 and 1.35R☉. CoMP is an imaging spectro-polarimeter, and
provides images of the corona taken at three different wavelength
positions centered on the 10747Å FeXIII coronal emission line. The
data were selected from CoMP observations taken between 2012 and 2016.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 78 120 Measured loop parameters and wave parameters
obtained from observations
--------------------------------------------------------------------------------
See also:
J/MNRAS/456/1542 : Coronal mass ejections transit times (Sudar+, 2016)
J/A+A/587/A29 : Time and positions of coronal bright points (Sudar+, 2016)
J/other/SoPh/294.144 : Coronal hole parameters (Heinemann+, 2019)
J/ApJS/241/31 : Kink oscillations of solar coronal loops (Nechaeva+, 2019)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/120] Internal loop index number
5- 12 F8.2 arcsec X [-1163/1140] Solar X position
14- 21 F8.2 arcsec Y [-1075/1060] Solar Y position
23- 32 A10 "Y/M/D" Date Observation date
34- 38 F5.1 Mm Length [42/585] Half-loop length
40- 43 F4.2 Mm e_Length [3.23] Uncertainty in Length
45- 51 F7.2 --- xi [-163/299] Equilibrium parameter
53- 57 F5.2 --- e_xi [0.5/50] Uncertainty in xi
59- 62 F4.2 --- PRatio [0.45/2.61] Power ratio
64- 67 F4.2 --- e_PRatio [0.17/1.1] Uncertainty in PRatio
69- 73 F5.1 km/s PVel [202/738] Phase velocity
75- 78 F4.1 km/s e_PVel [2/43] Uncertainty in PVel
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 30-Jan-2023