|
| | | | |
| | | |
| Stat |
Members: 3286
Articles: 2'244'908
Articles rated: 2592
19 August 2022 |
|
| | | | |
|
Article overview
| |
|
|
A Kennicutt-Schmidt relation at molecular cloud scales and beyond | | Sergey A. Khoperskov
; Evgenii O. Vasiliev
; | | Date: |
27 Feb 2017 | | Abstract: | Using N-body/gasdynamic simulations of a Milky Way-like galaxy we analyse a
Kennicutt-Schmidt relation, $Sigma_{SFR} propto Sigma_{gas}^N$, at different
spatial scales. We simulate synthetic observations in CO lines and UV band. We
adopt the star formation rate defined in two ways: based on free fall collapse
of a molecular cloud - $Sigma_{SFR, cl}$, and calculated by using a UV flux
calibration - $Sigma_{SFR, UV}$. We study a KS relation for spatially smoothed
maps with effective spatial resolution from molecular cloud scales to several
hundred parsecs. We find that for spatially and kinematically resolved
molecular clouds the $Sigma_{SFR, cl} propto Sigma_{
m gas}^N$ relation
follows the power-law with index $N approx 1.4$. Using UV flux as SFR
calibrator we confirm a systematic offset between the $Sigma_{
m UV}$ and
$Sigma_{
m gas}$ distributions on scales compared to molecular cloud sizes.
Degrading resolution of our simulated maps for surface densities of gas and
star formation rates we establish that there is no relation $Sigma_{
m SFR,
UV} - Sigma_{
m gas}$ below the resolution $sim 50$ pc. We find a transition
range around scales $sim 50-120$ pc, where the power-law index $N$ increases
from 0 to 1-1.8 and saturates for scales larger $sim 120$ pc. A value of the
index saturated depends on a surface gas density threshold and it becomes
steeper for higher $Sigma_{gas}$ threshold. Averaging over scales with size of
$>150$ pc the power-law index $N$ equals 1.3-1.4 for surface gas density
threshold $sim 5 M_odot$pc$^{-2}$. At scales $>120$ pc surface SFR densities
determined by using CO data and UV flux, $Sigma_{
m SFR, UV}/Sigma_{
m SFR,
cl}$, demonstrate a discrepancy about a factor of 3. We argue that this may be
originated from overestimating (constant) values of conversion factor, star
formation efficiency or UV calibration used in our analysis. | | Source: | arXiv, 1702.8562 | | Services: | Forum | Review | PDF | Favorites | |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser CCBot/2.0 (https://commoncrawl.org/faq/)
|
| |
|
|
|
|
News, job offers and information for researchers and scientists:
| |
REGISTER