Jets in Polar Coronal Holes

Scullion, Eamon, Popescu, M. D., Banerjee, Dipankar, Doyle, John Gerard and Erdélyi, Robert (2009) Jets in Polar Coronal Holes. The Astrophysical Journal, 704 (2). pp. 1385-1395. ISSN 0004-637X

Full text not available from this repository.

Abstract

Here, we explore the nature of small-scale jet-like structures and their possible relation to explosive events and other known transient features, like spicules and macrospicules, using high-resolution spectroscopy obtained with the Solar and Heliospheric Observatory/Solar Ultraviolet Measurements of Emitted Radiation instrument. We present a highly resolved spectroscopic analysis and line parameter study of time-series data for jets occurring on-disk and off-limb in both a northern and a southern coronal hole. The analysis reveals many small-scale transients which rapidly propagate between the mid-transition region (N IV 765 line formation: 140,000 K) and the lower corona (Ne VIII 770 line formation: 630,000 K). In one example, a strong jet-like event is associated with a cool feature not present in the Ne VIII 770 line radiance or Doppler velocity maps. Another similar event is observed, but with a hot component, which could be perceived as a blinker. Our data reveal fast, repetitive plasma outflows with blueshift velocities of 145 km s-1 in the lower solar atmosphere. The data suggest a strong role for smaller jets (spicules), as a precursor to macrospicule formation, which may have a common origin with explosive events.

Item Type:	Article
Uncontrolled Keywords:	line: profiles – Sun: chromosphere – Sun: transition region – Sun: UV radiation – techniques: spectroscopic
Subjects:	F500 Astronomy
Department:	Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Depositing User:	Paul Burns
Date Deposited:	15 Jan 2019 10:09
Last Modified:	11 Oct 2019 14:34
URI:	http://nrl.northumbria.ac.uk/id/eprint/37587

Downloads