The impact of dust on the sizes of galaxies in the Epoch of Reionization
Research output: Contribution to journal › Journal article › Research › peer-review
Standard
The impact of dust on the sizes of galaxies in the Epoch of Reionization. / Marshall, Madeline A.; Wilkins, Stephen; Di Matteo, Tiziana; Roper, William J.; Vijayan, Aswin P.; Ni, Yueying; Feng, Yu; Croft, Rupert A. C.
In: Monthly Notices of the Royal Astronomical Society, Vol. 511, No. 4, 08.03.2022, p. 5475-5491.Research output: Contribution to journal › Journal article › Research › peer-review
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - The impact of dust on the sizes of galaxies in the Epoch of Reionization
AU - Marshall, Madeline A.
AU - Wilkins, Stephen
AU - Di Matteo, Tiziana
AU - Roper, William J.
AU - Vijayan, Aswin P.
AU - Ni, Yueying
AU - Feng, Yu
AU - Croft, Rupert A. C.
PY - 2022/3/8
Y1 - 2022/3/8
N2 - We study the sizes of galaxies in the Epoch of Reionization using a sample of similar to 100 000 galaxies from the BLUETIDES cosmological hydrodynamical simulation from z = 7 to 11. We measure the galaxy sizes from stellar mass and luminosity maps, defining the effective radius as the minimum radius that could enclose the pixels containing 50 per cent of the total mass/light in the image. We find an inverse relationship between stellar mass and effective half-mass radius, suggesting that the most massive galaxies are more compact and dense than lower mass galaxies, which have flatter mass distributions. We find a mildly negative relation between intrinsic far-ultraviolet luminosity and size, while we find a positive size-luminosity relation when measured from dust-attenuated images. This suggests that dust is the predominant cause of the observed positive size-luminosity relation, with dust preferentially attenuating bright sightlines resulting in a flatter emission profile and thus larger measured effective radii. We study the size-luminosity relation across the rest-frame ultraviolet and optical, and find that the slope decreases at longer wavelengths; this is a consequence of the relation being caused by dust, which produces less attenuation at longer wavelengths. We find that the far-ultraviolet size-luminosity relation shows mild evolution from z = 7 to 11, and galaxy size evolves with redshift as R proportional to (1 + z)(-m), where m = 0.662 +/- 0.009. Finally, we investigate the sizes of z = 7 quasar host galaxies, and find that while the intrinsic sizes of quasar hosts are small relative to the overall galaxy sample, they have comparable sizes when measured from dust-attenuated images.
AB - We study the sizes of galaxies in the Epoch of Reionization using a sample of similar to 100 000 galaxies from the BLUETIDES cosmological hydrodynamical simulation from z = 7 to 11. We measure the galaxy sizes from stellar mass and luminosity maps, defining the effective radius as the minimum radius that could enclose the pixels containing 50 per cent of the total mass/light in the image. We find an inverse relationship between stellar mass and effective half-mass radius, suggesting that the most massive galaxies are more compact and dense than lower mass galaxies, which have flatter mass distributions. We find a mildly negative relation between intrinsic far-ultraviolet luminosity and size, while we find a positive size-luminosity relation when measured from dust-attenuated images. This suggests that dust is the predominant cause of the observed positive size-luminosity relation, with dust preferentially attenuating bright sightlines resulting in a flatter emission profile and thus larger measured effective radii. We study the size-luminosity relation across the rest-frame ultraviolet and optical, and find that the slope decreases at longer wavelengths; this is a consequence of the relation being caused by dust, which produces less attenuation at longer wavelengths. We find that the far-ultraviolet size-luminosity relation shows mild evolution from z = 7 to 11, and galaxy size evolves with redshift as R proportional to (1 + z)(-m), where m = 0.662 +/- 0.009. Finally, we investigate the sizes of z = 7 quasar host galaxies, and find that while the intrinsic sizes of quasar hosts are small relative to the overall galaxy sample, they have comparable sizes when measured from dust-attenuated images.
KW - galaxies: evolution
KW - galaxies: high-redshift
KW - galaxies: fundamental parameters
KW - galaxies: structure
KW - MASS ASSEMBLY GAMA
KW - DARK-AGES REIONIZATION
KW - QUASAR HOST GALAXIES
KW - BLACK-HOLES
KW - STAR-FORMATION
KW - COSMOLOGICAL SIMULATIONS
KW - 1ST GALAXIES
KW - EVOLUTION
KW - REDSHIFT
KW - GROWTH
U2 - 10.1093/mnras/stac380
DO - 10.1093/mnras/stac380
M3 - Journal article
VL - 511
SP - 5475
EP - 5491
JO - Royal Astronomical Society. Monthly Notices
JF - Royal Astronomical Society. Monthly Notices
SN - 0035-8711
IS - 4
ER -
ID: 319534902