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Astrometry and infrared observations of the Mira variable stars AP Lyncis, V837 Herculis, and BX Camelopardalis: Implications for the period-luminosity relation of the Milky Way
Fujimoto, Masayuki Y.; Nakagawa, Akiharu; Nagayama, Takahiro +6 more
AP Lyn and V837 Her are long-period Mira variable stars in the Milky Way. We performed VLBI Exploration of Radio Astrometry (VERA) phase-referenced observations towards H2O masers associated with AP Lyn and V837 Her. The annual parallaxes of AP Lyn and V837 Her were obtained to be 2.008 ± 0.038 mas and 1.090 ± 0.014 mas, corresponding t…
Discovery of a transient X-ray source Suzaku J1305-4930 in NGC 4945
Yoneyama, Tomokage; Hayashida, Kiyoshi; Matsumoto, Hironori +3 more
We report the serendipitous discovery of a transient X-ray source, Suzaku J1305-4930, ∼3 kpc southwest of the nucleus of the Seyfert 2 galaxy NGC 4945. Among the seven Suzaku observations of NGC 4945 from 2005 to 2011, Suzaku J1305-4930 was detected four times in July and August in 2010. The X-ray spectra are better approximated with a multi-color…
A systematic study of Galactic infrared bubbles along the Galactic plane with AKARI and Herschel. II. Spatial distributions of dust components around the bubbles
Oyabu, Shinki; Kaneda, Hidehiro; Ishihara, Daisuke +7 more
Galactic infrared (IR) bubbles, which can be seen as shell-like structures at mid-IR wavelengths, are known to possess massive stars within their shell boundaries. In our previous study (Hanaoka, 2019, PASJ, 71, 6), we expanded the research area to the whole Galactic plane (0° ≤ l ≤ 360°, |b| ≤ 5°) and studied systematic differences in the shell m…
Discovery of recombining plasma associated with the candidate supernova remnant G189.6+3.3 with Suzaku
Nobukawa, Kumiko K.; Yamauchi, Shigeo; Pannuti, Thomas G. +1 more
We present the results of an X-ray spectral analysis of the northeast region of the candidate supernova remnant G189.6+3.3 with Suzaku. K-shell lines from highly ionized Ne, Mg, Si, and S were detected in the spectrum for the first time. In addition, a radiative recombining continuum (RRC) from He-like Si was clearly seen near 2.5 keV. This detect…
ALMA band 8 observations of DLA 2233+131 at z = 3.150
Kajisawa, Masaru; Nagao, Tohru; Kashikawa, Nobunari +8 more
We present our ALMA Band 8 observations of a damped Ly $\alpha$ absorption (DLA) system at $z = 3.150$ observed in the spectrum of the quasar Q2233+131 at $z = 3.295$ . The optical counterpart of this DLA has been identified and it shows a double-peaked Ly $\alpha$ emission line. Since one possible origin of DLAs at high redshift is an outflowing …
Magnetic field structure of the Galactic plane from differential analysis of interstellar polarization
Nagata, Tetsuya; Zenko, Tetsuya; Matsunaga, Noriyuki +4 more
A new method for measuring the global magnetic field structure of the Galactic plane is presented. We have determined the near-infrared polarization of field stars around 52 Cepheids found in recent surveys toward the Galactic plane. The Cepheids are located at the galactic longitudes $-10^{\circ} \le l \le +10.^{\!\!\!\circ }5$ and latitudes $-0.…
Star formation rates in the L 1482 filament of the California molecular cloud
Shimajiri, Yoshito; Sunada, Kazuyoshi; Dobashi, Kazuhito +7 more
We measured the trigonometric parallax of the H2O maser source associated with the L 1482 molecular filament hosting the most massive young star, LkHα 101, in the California molecular cloud. The measured parallax is 1.879 ± 0.096 mas, corresponding to the distance of 532 ± 28 pc. This parallax is consistent with that of the nearby star …
Discovery of annular X-ray emission centered on MAXI J1421-613: Dust-scattering X-rays?
Nobukawa, Masayoshi; Nobukawa, Kumiko K.; Yamauchi, Shigeo
We report the discovery of an annular emission of $\sim\!\! {3^{\prime }}\!-\!{9^{\prime }}$ radius around the center of a transient source, the X-ray burster MAXI J1421-613, in the Suzaku follow-up analysis. The spectrum of the annular emission shows no significant emission-line structure, and is well explained by an absorbed power-law model with…
The long-term optical activity of the propellers AE Aquarii and AR Scorpii
Šimon, Vojtěch
This analysis of the long-term optical activity of the propellers AE Aqr and AR Sco uses data from the Catalina Real-time Transient Survey, DASCH, and AAVSO. The site and character of the emissions from the phenomena caused by the magnetic field of the white dwarf (WD) vary from system to system. The histogram of intensities of the ensemble of fla…
86-GHz SiO masers in Galactic centre OH/IR stars
Messineo, Maria; Omont, Alain; Sjouwerman, Lorant O. +1 more
We present results on a search for 86.243-GHz SiO (J = 2→1, $v$ = 1) maser emission toward 67 OH/IR stars located near the Galactic centre. We detected 32 spectral peaks, of which 28 correspond to SiO maser lines arising from the envelopes of these OH/IR stars. In OH/IR stars, we obtained an SiO maser detection rate of about $40\%$ . We serendipit…