First VLBI Imaging of SiO $v=0$, $J=1 \rightarrow 0$ Masers in VY Canis Majoris
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866913724445491200 |
|---|---|
| author | Shinnaga, Hiroko Oyadomari, Miyako Imai, Hiroshi Oyama, Tomoaki Claussen, Mark J. Shimojo, Masumi Yamamoto, Satoshi Richards, Anita M. S. Etoka, Sandra Gray, Malcolm Suzuki, Takeru |
| author_facet | Shinnaga, Hiroko Oyadomari, Miyako Imai, Hiroshi Oyama, Tomoaki Claussen, Mark J. Shimojo, Masumi Yamamoto, Satoshi Richards, Anita M. S. Etoka, Sandra Gray, Malcolm Suzuki, Takeru |
| contents | We achieved the first VLBI detections of the ground vibrational state ($v=0$) $^{28}$SiO (hereafter, SiO) and $^{29}$SiO masers of the $J=1\rightarrow 0$ rotational transitions, towards the 25 \Msun ~red supergiant (RSG) star, VY Canis Majoris (VY CMa), taking advantage of the high sensitivity of the VLBI Exploration of Radio Astrometry (VERA) telescopes that coordinate with the Nobeyama 45 m telescope. In addition, we successfully detected the SiO $J=1\rightarrow 0$ transition in the $v=3$ state towards VY CMa for the first time with VLBI. The SiO $J=1\rightarrow 0$ maser spot in $v=0$ state was detected in the cross-power spectra taken with the baselines involving the Nobeyama 45-m telescope. The combination of previously reported absolute astrometry and the relative astrometry technique allowed us to derive the location of the SiO $v=0$ maser spot, {(RA, DEC) = ( 7${\rm ^h}$ 22${\rm ^m}$ 58.$^{\rm s}$32, $-$25$^{\circ}$ 46$^{\prime}$ 3.$^{\prime\prime}$4) in J2000 at an absolute positional accuracy of $\sim$100 milliarcseconds (mas). The SiO $v=0$ maser spot is offset by the amount of ($Δ$RA, $Δ$DEC)=($-$150, $-$300) (mas) to the southwest of the stellar position, suggesting that the $v = 0$ maser spot is associated with its outflow activity.} This observational study demonstrates that the brightest SiO $v=0$ maser spot is compact (3 mas), producing an extremely high brightness of $\sim$ 10$^7$ K. This indicates that the SiO $v=0$ maser action may originate from strong shocks in the stellar wind emanating from this extreme RSG that leads to its intense mass ejection. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2503_05250 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | First VLBI Imaging of SiO $v=0$, $J=1 \rightarrow 0$ Masers in VY Canis Majoris Shinnaga, Hiroko Oyadomari, Miyako Imai, Hiroshi Oyama, Tomoaki Claussen, Mark J. Shimojo, Masumi Yamamoto, Satoshi Richards, Anita M. S. Etoka, Sandra Gray, Malcolm Suzuki, Takeru Solar and Stellar Astrophysics Astrophysics of Galaxies We achieved the first VLBI detections of the ground vibrational state ($v=0$) $^{28}$SiO (hereafter, SiO) and $^{29}$SiO masers of the $J=1\rightarrow 0$ rotational transitions, towards the 25 \Msun ~red supergiant (RSG) star, VY Canis Majoris (VY CMa), taking advantage of the high sensitivity of the VLBI Exploration of Radio Astrometry (VERA) telescopes that coordinate with the Nobeyama 45 m telescope. In addition, we successfully detected the SiO $J=1\rightarrow 0$ transition in the $v=3$ state towards VY CMa for the first time with VLBI. The SiO $J=1\rightarrow 0$ maser spot in $v=0$ state was detected in the cross-power spectra taken with the baselines involving the Nobeyama 45-m telescope. The combination of previously reported absolute astrometry and the relative astrometry technique allowed us to derive the location of the SiO $v=0$ maser spot, {(RA, DEC) = ( 7${\rm ^h}$ 22${\rm ^m}$ 58.$^{\rm s}$32, $-$25$^{\circ}$ 46$^{\prime}$ 3.$^{\prime\prime}$4) in J2000 at an absolute positional accuracy of $\sim$100 milliarcseconds (mas). The SiO $v=0$ maser spot is offset by the amount of ($Δ$RA, $Δ$DEC)=($-$150, $-$300) (mas) to the southwest of the stellar position, suggesting that the $v = 0$ maser spot is associated with its outflow activity.} This observational study demonstrates that the brightest SiO $v=0$ maser spot is compact (3 mas), producing an extremely high brightness of $\sim$ 10$^7$ K. This indicates that the SiO $v=0$ maser action may originate from strong shocks in the stellar wind emanating from this extreme RSG that leads to its intense mass ejection. |
| title | First VLBI Imaging of SiO $v=0$, $J=1 \rightarrow 0$ Masers in VY Canis Majoris |
| topic | Solar and Stellar Astrophysics Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2503.05250 |