Atomic Astrophysics Group, University of Cambridge

Statistical Study of Jets Emanating from the Periphery of Active Regions

Sargam Mulay1,2, Durgesh Tripathi 2 , Giulio Del Zanna1 , Helen Mason1

1Department of Applied Mathematics and Theoretical Physics, University of Cambridge, CB3 0WA, UK2Inter-University Centre for Astronomy and Astrophysics, Post Bag-4, Ganeshkhind, Pune 411007, India

The AIA/SDO observed a jet on 2 August 2010 originating from the

edge of active region NOAA 11092 (N13 E07). The jet is observed in

all wavelength channels of AIA. The jet started its activity at 17:10 UT

and ended 17:35 UT.

Fig. 1 shows the jet evolution at 17:26 UT in all AIA passbands. The

untwisting nature of jet plasma is seen with a small loop at the base.

Using AIA wavelength channels sensitive to coronal temperatures, we find the line-of-sight DEM using the

method of regularized inversion (Hannah & Kontar 2012). The method allows the reconstruction of the DEM

for a selected area in a range of temperature log10

T = 5.5 to log10

T = 7.5 at Δ log T = 0.1 intervals. The latest

version of the AIA response function (including the new CHIANTI v.8, Del Zanna et al. 2015) and Feldman

1992, coronal abundance was used.

Fig. 4 Column 1 : shows the jet in H-alpha at 17:26 UT observed by BBSO. Column 2 and 3 : show the jet

in AIA 193 Å channel with 3-6 keV and 6-12 keV RHESSI contours overplotted. Column 4 : shows the

nonthermal Type III radio burst observed by WIND/WAVES which is co-temporal with the jet evolution. The

presence of HXR source and the non-thermal Type III radio burst indicates the signature of particle

acceleration.

Fig. 2 Left panel : shows the jet evolution in AIA 193 Å channel and

white line shows the artificial slit which is used to produce time-

distance plot. Right panel : time-distance plot along the jet spire. The

white dashed line is used for the velocity calculation, which is found to

be 236 km/s.

Fig. 3 HMI line-of-sight magnetogram during the jet evolution shows

the negative polarity sunspot (black in colour) surrounded by positive

polarity (white in colour). The white arrow shows there is an

emergence of positive polarity at the edge of the sunspot during the

jet evolution.

Summary :

1) 20 EUV active region jets have been studied.

2) Velocities range from 87 to 730 km/s with an average of 408 km/s.

3) The jets are associated with nonthermal type III radio burst and RHESSI hard X-ray emission. This

indicates the signature of particle acceleration.

4) Studies of the HMI data indicate flux emergence in some of the cases and disappearance in others.

5) The DEM for the jets generally peaks at around log T = 6.3 K. We are unsure of the validity of the high

temperature component (> log T = 7 K). We are still investigating this.

Abstract : We have studied 20 EUV active region jets observed between June 2010 and June 2013. We select the events observed on solar disk within +/- 60° latitude to

avoid any line-of-sight effects. These jets occurred at the periphery of the active region/sunspots and most of them are co-temporal with nonthermal Type III radio bursts

observed by the Wind//WAVES spacecraft in the 20 kHz to 13 MHz frequency range. These jets were observed using Atmospheric Imaging Assembly (AIA) instrument

onboard Solar Dynamic Observatory (SDO). Using AIA wavelength channels sensitive to coronal temperatures, we find the line-of-sight Differential Emission Measure

(DEM) using the method of regularized inversion (Hannah and Kontar 2012). We are still investigating the high temperature component seen in the jet spire and the

footpoint. We have used the Helioseismic and Magnetic Imager (HMI) onboard SDO to get the information about the photospheric magnetic field. From the RHESSI

observations, it has been observed that EUV jets often share the same source region as the HXR emission. Here, we present the results for one of the jets.

References :

Del Zanna, G., Dere, K.P., Young, P.R. et al. 2015, submitted

Feldman, U., 1992, Physica Scripta, 46, 202

Hannah, I., Kontar, E., 2012, A&A, 539, A146

Fig. 5 Left panel : (top images) shows AIA 171 Å image of pre-jet phase and jet. The region in overplotted

small box is used for the DEM analysis. Left panel : (bottom image) DEM result for the jet (black curve)

and for the pre-jet phase (red curve). The DEM peaks at log T = 6.3 K. We are still investigating the high

temperature component seen in the jet spire. Right panel : column 1 and 3 : shows the evolution of jet in

different AIA channels, column 2 and 4 : shows the reconstructed maps from the DEM results which agree

well with the AIA observations.

Atomic Astrophysics Group, University of Cambridge

Statistical Study of Jets Emanating from the Periphery of Active Regions

Sargam Mulay1,2, Durgesh Tripathi 2 , Giulio Del Zanna1 , Helen Mason1

1Department of Applied Mathematics and Theoretical Physics, University of Cambridge, CB3 0WA, UK2Inter-University Centre for Astronomy and Astrophysics, Post Bag-4, Ganeshkhind, Pune 411007, India

Abstract : We have studied 20 EUV active region jets observed between June 2010 and June 2013. We select the events observed on solar disk within +/- 60° latitude to

avoid any line-of-sight effects. These jets occurred at the periphery of the active region/sunspots and most of them are co-temporal with nonthermal Type III radio bursts

observed by the Wind//WAVES spacecraft in the 20 kHz to 13 MHz frequency range. These jets were observed using Atmospheric Imaging Assembly (AIA) instrument

onboard Solar Dynamic Observatory (SDO). Using AIA wavelength channels sensitive to coronal temperatures, we find the line-of-sight Differential Emission Measure

(DEM) using the method of regularized inversion (Hannah and Kontar 2012). We are still investigating the high temperature component seen in the jet spire and the

footpoint. We have used the Helioseismic and Magnetic Imager (HMI) onboard SDO to get the information about the photospheric magnetic field. From the RHESSI

observations, it has been observed that EUV jets often share the same source region as the HXR emission. Here, we present the list of jets.

Date Time (UT) in 193 Å

Active Region GOES X-ray Flare Type III radio burst

RHESSI Hard X-rays

Jet Velocity (km/s)

Remark

2010 July 20 02:07 – 02:34 Pore - 02:11 - 352 Negative polarity emergence

2010 Sept. 17 00:14 – 00:19 11106 (S20 W09)

B 5.7 (00:14) 00:20 - 194.6 Negative Polarity disappearance

2011 Feb. 14 12:51 – 12:58 11158 (S20 W17)

C 4.9 (12:41) 12:50 3-6, 6-12, 12-25 208 Positive polarity emergence and disappearance

2011 Dec. 11 03:17 – 04:26 11374 (S17 E27)

- 03:20 3-6, 6-12 165.05 Positive polarity emergence

2012 Mar. 05 21:50 – 22:00 11429 (N18 E41)

M 1.3 (22:26) 21:50 - 532.22 Negative polarity disappearance

2012 July 02 02:38 – 02:48 11513 (N16 W11) - 02:40 3-6, 6-12, 12-25 462.48 Positive polarity emergence

2012 Oct. 10 14:22 – 14:45 11585 (S20 W43)

C 2.1 (14:25) 14:25 6-12 259.64 Negative polarity emergence and disappearance

2013 Apr. 24 12:10 – 12:20 11726 (N13 W63)

11:45 3-6, 6-12 730.48 Positive polarity disappearance

2013 May 04 23:15 – 23:33 11734 (S19 W04)

C 1.3 (23:25) 23:10 3-6, 6-12, 12-25 283.35 Positive polarity disappearance

2013 June 17 08:41 – 09:04 11770 (S13 E13)

C 1.7 (07:19) 08:40 3-6, 6-12, 12-25 409.77 Negative polarity emergence and disappearance

2010 Aug. 02 17:10 - 17:35 11092 (N13 E07)

B 1.8 (17:21) 17:25 3-6, 6-12 236 Positive polarity emergence and disappearance

2011 Feb. 16 13:23 - 13:42 11158 (S21 W41)

- 13:20 3-6, 6-12, 12-25 207.8 Positive polarity emergence

2011 Mar. 01 12:54 - 13:08 11165 (S21 W00)

- 12:20 - 87.28 Negative polarity disappearance

2011 Mar. 07 21:33 - 22:12 11166 (N11 E13)

M 1.5 (21:45) 21:50 - 203.02 Negative polarity disappearance

2011 Dec. 11 12:14 - 12:39 11374 (S17 E27)

- 12:20 3-6, 6-12 278.4 Negative polarity disappearance

2011 Dec. 11 23:17 - 23:35 11374 (S17 E27)

- 23:10 3-6, 6-12 165.89 Negative Polarity disappearance

2013 Mar. 02 12:00 - 12:18 11681 (N17 W08)

B 6 (11:48) 11:50 - 210.89 Positive polarity disappearance

2013 Apr. 28 20:56 - 21:09 11731 (N09 E23)

C 1.5 (20:59) - - 320.53 Positive polarity emergence

2013 May 25 08:40 - 08:53 11748 (N12 W83)

- - 3-6, 6-12 322.77 Positive polarity emergence

2013 Jun. 18 15:12 – 15:55 11770 (S14 E02)

B 9.4 (15:14) 09:15 3-6, 6-12, 12-25 338.58 Positive polarity disappearance