Pilot KaVA monitoring on the M 87 jet: Confirming the inner jet structure and superluminal motions at sub-pc scales

Kazuhiro Hada; Jong Ho PARK; Motoki Kino; Kotaro Niinuma; Bong Won Sohn; Hyun Wook Ro; Taehyun Jung; Juan Carlos Algaba; Guang Yao Zhao; Sang Sung Lee; Kazunori Akiyama; Sascha Trippe; Kiyoaki Wajima; Satoko Sawada-Satoh; Fumie Tazaki; Ilje Cho; Jeffrey Hodgson; Jeong Ae Lee; Yoshiaki Hagiwara; Mareki Honma; Shoko Koyama; Junghwan Oh; Taeseak Lee; Hyemin Yoo; Noriyuki Kawaguchi; Duk Gyoo Roh; Se Jin Oh; Jae Hwan Yeom; Dong Kyu Jung; Chungsik Oh; Hyo Ryoung Kim; Ju Yeon Hwang; Do Young Byun; Se Hyung Cho; Hyun Goo Kim; Hideyuki Kobayashi; Katsunori M. Shibata

doi:10.1093/pasj/psx054

Pilot KaVA monitoring on the M 87 jet: Confirming the inner jet structure and superluminal motions at sub-pc scales

Kazuhiro Hada, Jong Ho PARK, Motoki Kino, Kotaro Niinuma, Bong Won Sohn, Hyun Wook Ro, Taehyun Jung, Juan Carlos Algaba, Guang Yao Zhao, Sang Sung Lee, Kazunori Akiyama, Sascha Trippe, Kiyoaki Wajima, Satoko Sawada-Satoh, Fumie Tazaki, Ilje Cho, Jeffrey Hodgson, Jeong Ae Lee, Yoshiaki Hagiwara, Mareki HonmaShoko Koyama, Junghwan Oh, Taeseak Lee, Hyemin Yoo, Noriyuki Kawaguchi, Duk Gyoo Roh, Se Jin Oh, Jae Hwan Yeom, Dong Kyu Jung, Chungsik Oh, Hyo Ryoung Kim, Ju Yeon Hwang, Do Young Byun, Se Hyung Cho, Hyun Goo Kim, Hideyuki Kobayashi, Katsunori M. Shibata

Department of Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

57 Scopus citations

Abstract

We report the initial results of our high-cadence monitoring program on the radio jet in the active galaxy M 87, obtained by the KVN and VERA Array (KaVA) at 22 GHz. This is a pilot study that preceded a larger KaVA–M 87 monitoring program, which is currently ongoing. The pilot monitoring was mostly performed every two to three weeks from 2013 December to 2014 June, at a recording rate of 1 Gbps, obtaining data for a total of ten epochs. We successfully obtained a sequence of good quality radio maps that revealed the rich structure of this jet from 1 mas to 20 mas, corresponding to physical scales (projected) of ∼0.1–2 pc (or ∼140–2800 Schwarzschild radii). We detected superluminal motions at these scales, together with a trend of gradual acceleration. The first evidence for such fast motions and acceleration near the jet base were obtained from recent VLBA studies at 43 GHz, and the fact that very similar kinematics are seen at a different frequency and time with a different instrument suggests that these properties are fundamental characteristics of this jet. This pilot program demonstrates that KaVA is a powerful VLBI array for studying the detailed structural evolution of the M 87 jet and also other relativistic jets.

Original language	English
Article number	71
Journal	Publications of the Astronomical Society of Japan
Volume	69
Issue number	4
DOIs	https://doi.org/10.1093/pasj/psx054
State	Published - 1 Aug 2017

Bibliographical note

Publisher Copyright:
� The Author 2017. Published by Oxford University Press on behalf of the Astronomical Society of Japan. All rights reserved.

Keywords

Galaxies: active
Galaxies: jets
Radio continuum: galaxies
Techniques: interferometric

Access to Document

10.1093/pasj/psx054

Cite this

Hada, K., Ho PARK, J., Kino, M., Niinuma, K., Sohn, B. W., Ro, H. W., Jung, T., Algaba, J. C., Zhao, G. Y., Lee, S. S., Akiyama, K., Trippe, S., Wajima, K., Sawada-Satoh, S., Tazaki, F., Cho, I., Hodgson, J., Lee, J. A., Hagiwara, Y., ... Shibata, K. M. (2017). Pilot KaVA monitoring on the M 87 jet: Confirming the inner jet structure and superluminal motions at sub-pc scales. Publications of the Astronomical Society of Japan, 69(4), Article 71. https://doi.org/10.1093/pasj/psx054

@article{ca7145a92753476f89728e0bc1df7c83,

title = "Pilot KaVA monitoring on the M 87 jet: Confirming the inner jet structure and superluminal motions at sub-pc scales",

abstract = "We report the initial results of our high-cadence monitoring program on the radio jet in the active galaxy M 87, obtained by the KVN and VERA Array (KaVA) at 22 GHz. This is a pilot study that preceded a larger KaVA–M 87 monitoring program, which is currently ongoing. The pilot monitoring was mostly performed every two to three weeks from 2013 December to 2014 June, at a recording rate of 1 Gbps, obtaining data for a total of ten epochs. We successfully obtained a sequence of good quality radio maps that revealed the rich structure of this jet from 1 mas to 20 mas, corresponding to physical scales (projected) of ∼0.1–2 pc (or ∼140–2800 Schwarzschild radii). We detected superluminal motions at these scales, together with a trend of gradual acceleration. The first evidence for such fast motions and acceleration near the jet base were obtained from recent VLBA studies at 43 GHz, and the fact that very similar kinematics are seen at a different frequency and time with a different instrument suggests that these properties are fundamental characteristics of this jet. This pilot program demonstrates that KaVA is a powerful VLBI array for studying the detailed structural evolution of the M 87 jet and also other relativistic jets.",

keywords = "Galaxies: active, Galaxies: jets, Radio continuum: galaxies, Techniques: interferometric",

author = "Kazuhiro Hada and {Ho PARK}, Jong and Motoki Kino and Kotaro Niinuma and Sohn, {Bong Won} and Ro, {Hyun Wook} and Taehyun Jung and Algaba, {Juan Carlos} and Zhao, {Guang Yao} and Lee, {Sang Sung} and Kazunori Akiyama and Sascha Trippe and Kiyoaki Wajima and Satoko Sawada-Satoh and Fumie Tazaki and Ilje Cho and Jeffrey Hodgson and Lee, {Jeong Ae} and Yoshiaki Hagiwara and Mareki Honma and Shoko Koyama and Junghwan Oh and Taeseak Lee and Hyemin Yoo and Noriyuki Kawaguchi and Roh, {Duk Gyoo} and Oh, {Se Jin} and Yeom, {Jae Hwan} and Jung, {Dong Kyu} and Chungsik Oh and Kim, {Hyo Ryoung} and Hwang, {Ju Yeon} and Byun, {Do Young} and Cho, {Se Hyung} and Kim, {Hyun Goo} and Hideyuki Kobayashi and Shibata, {Katsunori M.}",

year = "2017",

month = aug,

day = "1",

doi = "10.1093/pasj/psx054",

language = "English",

volume = "69",

journal = "Publications of the Astronomical Society of Japan",

issn = "0004-6264",

publisher = "Oxford University Press",

number = "4",

}

Hada, K, Ho PARK, J, Kino, M, Niinuma, K, Sohn, BW, Ro, HW, Jung, T, Algaba, JC, Zhao, GY, Lee, SS, Akiyama, K, Trippe, S, Wajima, K, Sawada-Satoh, S, Tazaki, F, Cho, I, Hodgson, J, Lee, JA, Hagiwara, Y, Honma, M, Koyama, S, Oh, J, Lee, T, Yoo, H, Kawaguchi, N, Roh, DG, Oh, SJ, Yeom, JH, Jung, DK, Oh, C, Kim, HR, Hwang, JY, Byun, DY, Cho, SH, Kim, HG, Kobayashi, H & Shibata, KM 2017, 'Pilot KaVA monitoring on the M 87 jet: Confirming the inner jet structure and superluminal motions at sub-pc scales', Publications of the Astronomical Society of Japan, vol. 69, no. 4, 71. https://doi.org/10.1093/pasj/psx054

TY - JOUR

T1 - Pilot KaVA monitoring on the M 87 jet

T2 - Confirming the inner jet structure and superluminal motions at sub-pc scales

AU - Hada, Kazuhiro

AU - Ho PARK, Jong

AU - Kino, Motoki

AU - Niinuma, Kotaro

AU - Sohn, Bong Won

AU - Ro, Hyun Wook

AU - Jung, Taehyun

AU - Algaba, Juan Carlos

AU - Zhao, Guang Yao

AU - Lee, Sang Sung

AU - Akiyama, Kazunori

AU - Trippe, Sascha

AU - Wajima, Kiyoaki

AU - Sawada-Satoh, Satoko

AU - Tazaki, Fumie

AU - Cho, Ilje

AU - Hodgson, Jeffrey

AU - Lee, Jeong Ae

AU - Hagiwara, Yoshiaki

AU - Honma, Mareki

AU - Koyama, Shoko

AU - Oh, Junghwan

AU - Lee, Taeseak

AU - Yoo, Hyemin

AU - Kawaguchi, Noriyuki

AU - Roh, Duk Gyoo

AU - Oh, Se Jin

AU - Yeom, Jae Hwan

AU - Jung, Dong Kyu

AU - Oh, Chungsik

AU - Kim, Hyo Ryoung

AU - Hwang, Ju Yeon

AU - Byun, Do Young

AU - Cho, Se Hyung

AU - Kim, Hyun Goo

AU - Kobayashi, Hideyuki

AU - Shibata, Katsunori M.

PY - 2017/8/1

Y1 - 2017/8/1

N2 - We report the initial results of our high-cadence monitoring program on the radio jet in the active galaxy M 87, obtained by the KVN and VERA Array (KaVA) at 22 GHz. This is a pilot study that preceded a larger KaVA–M 87 monitoring program, which is currently ongoing. The pilot monitoring was mostly performed every two to three weeks from 2013 December to 2014 June, at a recording rate of 1 Gbps, obtaining data for a total of ten epochs. We successfully obtained a sequence of good quality radio maps that revealed the rich structure of this jet from 1 mas to 20 mas, corresponding to physical scales (projected) of ∼0.1–2 pc (or ∼140–2800 Schwarzschild radii). We detected superluminal motions at these scales, together with a trend of gradual acceleration. The first evidence for such fast motions and acceleration near the jet base were obtained from recent VLBA studies at 43 GHz, and the fact that very similar kinematics are seen at a different frequency and time with a different instrument suggests that these properties are fundamental characteristics of this jet. This pilot program demonstrates that KaVA is a powerful VLBI array for studying the detailed structural evolution of the M 87 jet and also other relativistic jets.

AB - We report the initial results of our high-cadence monitoring program on the radio jet in the active galaxy M 87, obtained by the KVN and VERA Array (KaVA) at 22 GHz. This is a pilot study that preceded a larger KaVA–M 87 monitoring program, which is currently ongoing. The pilot monitoring was mostly performed every two to three weeks from 2013 December to 2014 June, at a recording rate of 1 Gbps, obtaining data for a total of ten epochs. We successfully obtained a sequence of good quality radio maps that revealed the rich structure of this jet from 1 mas to 20 mas, corresponding to physical scales (projected) of ∼0.1–2 pc (or ∼140–2800 Schwarzschild radii). We detected superluminal motions at these scales, together with a trend of gradual acceleration. The first evidence for such fast motions and acceleration near the jet base were obtained from recent VLBA studies at 43 GHz, and the fact that very similar kinematics are seen at a different frequency and time with a different instrument suggests that these properties are fundamental characteristics of this jet. This pilot program demonstrates that KaVA is a powerful VLBI array for studying the detailed structural evolution of the M 87 jet and also other relativistic jets.

KW - Galaxies: active

KW - Galaxies: jets

KW - Radio continuum: galaxies

KW - Techniques: interferometric

UR - http://www.scopus.com/inward/record.url?scp=85031939321&partnerID=8YFLogxK

U2 - 10.1093/pasj/psx054

DO - 10.1093/pasj/psx054

M3 - Article

AN - SCOPUS:85031939321

SN - 0004-6264

VL - 69

JO - Publications of the Astronomical Society of Japan

JF - Publications of the Astronomical Society of Japan

IS - 4

M1 - 71

ER -

Pilot KaVA monitoring on the M 87 jet: Confirming the inner jet structure and superluminal motions at sub-pc scales

Abstract

Bibliographical note

Keywords

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