B2 1308+326: a changing-look blazar or not?
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866913611494981632 |
|---|---|
| author | Pandey, Ashwani Hu, Chen Wang, Jian-Min Czerny, Bozena Chen, Yong-Jie Songsheng, Yu-Yang Wang, Yi-Lin Zhang, Hao Aceituno, Jesus |
| author_facet | Pandey, Ashwani Hu, Chen Wang, Jian-Min Czerny, Bozena Chen, Yong-Jie Songsheng, Yu-Yang Wang, Yi-Lin Zhang, Hao Aceituno, Jesus |
| contents | In our previous study, we identified a shift in the synchrotron peak frequency of the blazar B2 1308$+$326 from 10$^{12.9}$ Hz to 10$^{14.8}$ Hz during a flare, suggesting it could be a changing-look blazar (CLB). In this work, we investigate the CL behaviour of B2 1308+326 by analysing a newly acquired optical spectrum and comparing it with an archival spectrum. We find that between the two epochs, the continuum flux increased by a factor of $\sim$4.4, while the Mg II emission line flux decreased by a factor of 1.4$\pm$0.2. Additionally, the equivalent width of the Mg II line reduced from $\sim 20$ Å\ to $\sim 3$ Å, indicating an apparent shift from a flat-spectrum radio quasar (FSRQ) class to a BL Lacertae (BL Lac) class. Despite this apparent change, the ratio of accretion disk luminosity to Eddington luminosity remains $>$ 10$^{-2}$ during both epochs, indicating efficient accretion persists in B2 1308$+$326. The measured black hole mass remains consistent with an average $\log M_{\rm BH} = 8.44$ M$_{\odot}$. Our findings suggest that B2 1308$+$326 is not a genuine CLB, but rather an intrinsic FSRQ that emerges as a BL Lac during high-flux states due to enhanced non-thermal emission. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2412_10552 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | B2 1308+326: a changing-look blazar or not? Pandey, Ashwani Hu, Chen Wang, Jian-Min Czerny, Bozena Chen, Yong-Jie Songsheng, Yu-Yang Wang, Yi-Lin Zhang, Hao Aceituno, Jesus High Energy Astrophysical Phenomena Astrophysics of Galaxies In our previous study, we identified a shift in the synchrotron peak frequency of the blazar B2 1308$+$326 from 10$^{12.9}$ Hz to 10$^{14.8}$ Hz during a flare, suggesting it could be a changing-look blazar (CLB). In this work, we investigate the CL behaviour of B2 1308+326 by analysing a newly acquired optical spectrum and comparing it with an archival spectrum. We find that between the two epochs, the continuum flux increased by a factor of $\sim$4.4, while the Mg II emission line flux decreased by a factor of 1.4$\pm$0.2. Additionally, the equivalent width of the Mg II line reduced from $\sim 20$ Å\ to $\sim 3$ Å, indicating an apparent shift from a flat-spectrum radio quasar (FSRQ) class to a BL Lacertae (BL Lac) class. Despite this apparent change, the ratio of accretion disk luminosity to Eddington luminosity remains $>$ 10$^{-2}$ during both epochs, indicating efficient accretion persists in B2 1308$+$326. The measured black hole mass remains consistent with an average $\log M_{\rm BH} = 8.44$ M$_{\odot}$. Our findings suggest that B2 1308$+$326 is not a genuine CLB, but rather an intrinsic FSRQ that emerges as a BL Lac during high-flux states due to enhanced non-thermal emission. |
| title | B2 1308+326: a changing-look blazar or not? |
| topic | High Energy Astrophysical Phenomena Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2412.10552 |