Subjects: Astronomy submitted time 2024-03-26 Cooperative journals: 《天文学进展》
Abstract： The bar structure of disk galaxies, their environment, and overall star formation properties are known to be intricately linked. By utilizing data from the Galaxy Zoo DECaLS program, we have assembled the largest sample of strong bar, weak bar, and no bar galaxies with matching stellar mass distributions. We analyzed the specific star formation rates (sSFR) of these galaxies after controlling for environmental effects by matching the halo mass and phase space diagram of the dark matter halo in which the galaxy resides. Our findings suggest that the percentage of quenched galaxies in the barred galaxy sample is consistently higher than that in non-bar galaxies, with a more pronounced effect for strong bar galaxies. However, for galaxies that are still on the star formation main sequence, there is no significant difference in their sSFR distribution. These results suggest that the presence of a bar in a galaxy may rapidly transition some galaxies from being star-forming to quenched in a short period of time.
Subjects: Astronomy submitted time 2024-03-22 Cooperative journals: 《天文学进展》
Abstract： The bar structure of disk galaxies, their environment, and overall star formation properties are known to be intricately linked. By utilizing data from the Galaxy Zoo DECaLS program, we have assembled the largest sample of strong bar, weak bar, and no bar galaxies with matching stellar mass distributions. We analyzed the specific star formation rates (sSFR) of these galaxies after controlling for environmental effects by matching the halo mass and phase space diagram of the dark matter halo in which the galaxy resides. Our findings suggest that the percentage of quenched galaxies in the barred galaxy sample is consistently higher than that in non-bar galaxies, with a more pronounced effect for strong bar galaxies. However, for galaxies that are still on the star formation main sequence, there is no significant difference in their sSFR distribution. These results suggest that the presence of a bar in a galaxy may rapidly transition some galaxies from being star-forming to quenched in a short period of time.
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
P. T. Rahna
Zhen-Ya Zheng
Ana L. Chies-Santos
Zheng Cai
Daniele Spinoso
Isabel Marquez
Roderik Overzier
L. Raul Abramo
Silvia Bonoli
Carolina Kehrig
L. A. Diaz-Garcia
Mirjana Povic
Roberto Soria
Jose M. Diego
Tom Broadhurst
Rosa M. Gonzalez Delgado
Jailson Alcaniz
Narciso Benitez
Saulo. Carneiro
A. Javier Cenarro
Abstract： The Ly$\alpha$ emission is an important tracer of neutral gas in a circum-galactic medium (CGM) around high-z QSOs. The origin of Lya emission around QSOs is still under debate which has significant implications for galaxy formation and evolution. In this paper, we study Ly$\alpha$ nebulae around two high redshift QSOs, SDSS J141935.58+525710.7 at $z=3.218$ (hereafter QSO1) and SDSS J141813.40+525240.4 at $z=3.287$ (hereafter QSO2), from the miniJPAS survey within the AEGIS field. Using the contiguous narrow-band (NB) images from the miniJPAS survey and SDSS spectra, we analyzed their morphology, nature, and origin. We report the serendipitous detection of double-core Ly\almorphology around two QSOs which is rarely seen among other QSOs. The separations of the two Ly\al~cores are 11.07 $\pm$ 2.26 kpcs (1.47 $\pm$ 0.3$^{\prime\prime}$) and 9.73 $\pm$ 1.55 kpcs (1.31 $\pm$ 0.21$^{\prime\prime}$) with Ly$\alpha$~line luminosities of $\sim$ 3.35 $\times 10^{44}$ erg s $^{-1} $ and $\sim$ 6.99 $\times$ 10$^{44}$ erg s $^{-1}$ for QSO1 and QSO2, respectively. The miniJPAS NB images show evidence of extended Ly$\alpha$ and CIV morphology for both QSOs and extended HeII morphology for QSO1. These two QSOs may be potential candidates for the new enormous Lyman alpha nebula (ELAN) found from the miniJPAS survey due to their extended morphology in the shallow depth and relatively high Ly$\alpha$ luminosities. We suggest that galactic outflows are the major powering mechanism for the double-core Ly$\alpha$ morphology. Considering the relatively shallow exposures of miniJPAS, the objects found here could be the tip of the iceberg of a promising number of such objects that will be uncovered in the upcoming full J-PAS survey and deep IFU observations with 8-10m telescopes will be essential for constraining the underlying physical mechanism that is responsible for the double-cored morphology.
Peer Review Status:
Awaiting Review
Hits
YES
Hits
Downloads
Comment