急速なラジオバーストとそのホストの直接的な位置づけ
S Chatterjee1, C J Law2, R S Wharton1
1Cornell Center for Astrophysics and Planetary Science and Department of Astronomy, Cornell University, Ithaca, New York 14853, USA.
Nature
|January 6, 2017
まとめ
FRBは神秘的な宇宙の ラジオフラッシュです 繰り返されるFRB 121102の正確な局所化は,恒常的なラジオ源の近くにその起源を明らかにし,活発な銀河核または新しい銀河外の源を示唆しています.
科学分野:
- 天文学と天体物理学
- コスミック・トランシエンツ
- ラジオ天文学
背景:
- 急速無線爆発 (FRB) は,起源が不明の,数ミリ秒間の銀河外の無線閃光である.
- 過去のFRBの位置づけは,同位体や宿主銀河を特定するのに十分な精度がありませんでした.
- FRB 121102は FRB現象を理解するために不可欠な唯一の繰り返しFRB源です.
研究 の 目的:
- FRB 121102の 繰り返し発生する ラジオバーストの 準秒位を特定する
- FRB 121102の 持続的な無線源と 潜在的な光学的な相手を特定するために
- FRB 121102の起源と物理的性質を制限する
主な方法:
- 高時間解像度の無線干渉計観測を用いて,直接爆破画像を撮影した.
- 恒常源の角の大きさを決定するために,非常に長いベースライン干渉計 (VLBI) を使用した.
- 微弱な光学的対称性を探した.
主要な成果:
- FRB 121102のサブアーク秒の位置を特定し 恒常的な電波源から100ミリアーク秒以内の位置を特定しました
- 持続的な源は,非熱的連続スペクトルを示し,毎日の時間スケールで~10%の流動密度変動を示します.
- 微弱な光学同位体 (25度) が検出され,持続的な無線源の角サイズは<1.7ミリアーク秒です.
結論:
- FRB 121102の源は 銀河の起源と一致しない
- 発光源は 低輝度で活発な銀河核か 新種の銀河外物体かもしれません
- 微弱なFRBを信頼して関連付け,その起源を理解するために,サブアーク秒の局所化は不可欠です.
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