FATHOMER survey: III. Preliminary HI galaxy identification results
Fuente:
arXiv
Salvato in:
| Autori principali: | , , , , , , , , |
|---|---|
| Natura: | Preprint |
| Pubblicazione: |
2026
|
| Soggetti: | |
| Accesso online: | |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1866911531354030080 |
|---|---|
| author | Shu, Shuanghao Li, Yichao Yang, Wenxiu Wang, Jiaxin Hu, Wenkai Deng, Furen Zuo, Shifan Wang, Yougang Chen, Xuelei |
| author_facet | Shu, Shuanghao Li, Yichao Yang, Wenxiu Wang, Jiaxin Hu, Wenkai Deng, Furen Zuo, Shifan Wang, Yougang Chen, Xuelei |
| contents | We present the HI galaxy observation results of the FATHOMER (FAst neuTral HydrOgen intensity Mapping ExpeRiment), a pilot drift scan survey by the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The survey comprises 28 hours of observations over 7 nights in 2021, covering a $60\, °^2$ sky area in the frequency range 1.05-1.45 GHz. The HI galaxies are identified using both a matched-filtering algorithm and the SoFiA source-finding pipeline, which yield consistent detections. We derive the velocity width ($W_{50}$), flux density, and HI mass for detected galaxies. A total of 702 galaxies are identified with HI mass above $10^{6.2}\,{M_\odot}$, signal-to-noise ratio greater than 5, and redshift $z < 0.09$. Among these, 331 are previously known from the ALFALFA survey. Of the newly detected sources, 9 have spectroscopic confirmation from SDSS, 285 are matched to SDSS or DESI photometric data, and 77 lack optical counterparts--possible candidates for dark or faint galaxies. Comparison with ALFALFA shows that FAST enables detection of galaxies at higher redshifts and with lower HI fluxes, despite the radio frequency interference (RFI) and partial data masking. A preliminary HI mass function analysis reveals a higher characteristic mass and steeper low-mass slope than ALFALFA, indicating FAST's enhanced sensitivity to massive and distant HI systems. These results demonstrate FAST's strong potential for future deep HI surveys and highlight the importance of improved RFI mitigation and completeness correction. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2603_19777 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | FATHOMER survey: III. Preliminary HI galaxy identification results Shu, Shuanghao Li, Yichao Yang, Wenxiu Wang, Jiaxin Hu, Wenkai Deng, Furen Zuo, Shifan Wang, Yougang Chen, Xuelei Astrophysics of Galaxies We present the HI galaxy observation results of the FATHOMER (FAst neuTral HydrOgen intensity Mapping ExpeRiment), a pilot drift scan survey by the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The survey comprises 28 hours of observations over 7 nights in 2021, covering a $60\, °^2$ sky area in the frequency range 1.05-1.45 GHz. The HI galaxies are identified using both a matched-filtering algorithm and the SoFiA source-finding pipeline, which yield consistent detections. We derive the velocity width ($W_{50}$), flux density, and HI mass for detected galaxies. A total of 702 galaxies are identified with HI mass above $10^{6.2}\,{M_\odot}$, signal-to-noise ratio greater than 5, and redshift $z < 0.09$. Among these, 331 are previously known from the ALFALFA survey. Of the newly detected sources, 9 have spectroscopic confirmation from SDSS, 285 are matched to SDSS or DESI photometric data, and 77 lack optical counterparts--possible candidates for dark or faint galaxies. Comparison with ALFALFA shows that FAST enables detection of galaxies at higher redshifts and with lower HI fluxes, despite the radio frequency interference (RFI) and partial data masking. A preliminary HI mass function analysis reveals a higher characteristic mass and steeper low-mass slope than ALFALFA, indicating FAST's enhanced sensitivity to massive and distant HI systems. These results demonstrate FAST's strong potential for future deep HI surveys and highlight the importance of improved RFI mitigation and completeness correction. |
| title | FATHOMER survey: III. Preliminary HI galaxy identification results |
| topic | Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2603.19777 |