Discovering High-$z$ BL Lacs Using Swift/UVOT and SARA Observations with the Dropout Technique
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_ | 1866918202599014400 |
|---|---|
| author | Sheng, Y. Imam, K. Kaur, A. Ajello, M. Domínguez, A. Rau, A. Cenko, S. B. Greiner, J. Hartmann, D. H. Circiello, A. Cox, I. Joffre, S. Mcdaniel, A. Rajguru, G. Silver, R. Torres-Albá, N. Webber, A. |
| author_facet | Sheng, Y. Imam, K. Kaur, A. Ajello, M. Domínguez, A. Rau, A. Cenko, S. B. Greiner, J. Hartmann, D. H. Circiello, A. Cox, I. Joffre, S. Mcdaniel, A. Rajguru, G. Silver, R. Torres-Albá, N. Webber, A. |
| contents | Measuring spectroscopic redshifts for BL Lacertae (BL Lac) objects, a class of blazar, is challenging because their optical spectrum lacks, or has weak, emission lines ( equivalent width $\leqslant5Å$). In this situation, alternative techniques are necessary for the estimation of distances to these sources. In this paper, we estimate the redshift by the photometric dropout technique for a sample of 64 blazars (59 BL Lacs and five blazar candidates of uncertain type). Two telescopes are utilized to observe the sample. The Ultraviolet/Optical Telescope (UVOT) on board {\it Swift} ({\it Swift}/UVOT) observes sources in $uvw2,\ uvm2,\ uvw1,\ u,\ b,\ v$ filters, while the ground-based telescopes SARA-CT/RM observed sources in $g',\ r,' \ i',\ z'$ filters. We fit the photometric data with the LePHARE package and report four new high-$z$ ($z>1.3$) BL Lacs at $2.03^{+0.07}_{-0.05}$, $1.84^{+0.10}_{-0.03}$, $2.04^{+0.16}_{-0.14}$, and $2.93^{+0.01}_{-0.04}$ as well as upper limits for 50 sources. This work increased the number of high-$z$ BL Lacs found by this method up to 23. The high-$z$ sources are discussed in the context of the cosmic gamma-ray horizon, blazar sequence, Fermi blazar divide, and masquerading BL Lacs. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2409_16236 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Discovering High-$z$ BL Lacs Using Swift/UVOT and SARA Observations with the Dropout Technique Sheng, Y. Imam, K. Kaur, A. Ajello, M. Domínguez, A. Rau, A. Cenko, S. B. Greiner, J. Hartmann, D. H. Circiello, A. Cox, I. Joffre, S. Mcdaniel, A. Rajguru, G. Silver, R. Torres-Albá, N. Webber, A. High Energy Astrophysical Phenomena Measuring spectroscopic redshifts for BL Lacertae (BL Lac) objects, a class of blazar, is challenging because their optical spectrum lacks, or has weak, emission lines ( equivalent width $\leqslant5Å$). In this situation, alternative techniques are necessary for the estimation of distances to these sources. In this paper, we estimate the redshift by the photometric dropout technique for a sample of 64 blazars (59 BL Lacs and five blazar candidates of uncertain type). Two telescopes are utilized to observe the sample. The Ultraviolet/Optical Telescope (UVOT) on board {\it Swift} ({\it Swift}/UVOT) observes sources in $uvw2,\ uvm2,\ uvw1,\ u,\ b,\ v$ filters, while the ground-based telescopes SARA-CT/RM observed sources in $g',\ r,' \ i',\ z'$ filters. We fit the photometric data with the LePHARE package and report four new high-$z$ ($z>1.3$) BL Lacs at $2.03^{+0.07}_{-0.05}$, $1.84^{+0.10}_{-0.03}$, $2.04^{+0.16}_{-0.14}$, and $2.93^{+0.01}_{-0.04}$ as well as upper limits for 50 sources. This work increased the number of high-$z$ BL Lacs found by this method up to 23. The high-$z$ sources are discussed in the context of the cosmic gamma-ray horizon, blazar sequence, Fermi blazar divide, and masquerading BL Lacs. |
| title | Discovering High-$z$ BL Lacs Using Swift/UVOT and SARA Observations with the Dropout Technique |
| topic | High Energy Astrophysical Phenomena |
| url | https://arxiv.org/abs/2409.16236 |