English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

We present results from the MOSFIRE Deep Evolution Field (MOSDEF) survey onbroad flux from the nebular emission lines H$\alpha$, [NII], [OIII], H$\beta$,and [SII]. The sample consists of 127 star-forming galaxies at $1.37 < z <2.61$ and 84 galaxies at $2.95 < z < 3.80$. We decompose the emission linesusing narrow ($\text{FWHM} < 275 \ \text{km s}^{-1}$) and broad ($\text{FWHM} >300 \ \text{km s}^{-1}$) Gaussian components for individual galaxies andstacks. Broad emission is detected at $>3\sigma$ in $<10$% of galaxies and thebroad flux accounts for 10-70% of the total flux. We find a slight increase inbroad to narrow flux ratio with mass but note that we cannot reliably detectbroad emission with $\text{FWHM} < 275 \ \text{km s}^{-1}$, which may besignificant at low masses. Notably, there is a correlation between highersignal-to-noise (S/N) spectra and a broad component detection indicating a S/Ndependence in our ability to detect broad flux. When placed on the N2-BPTdiagram ([OIII]/H$\beta$ vs. [NII]/H$\alpha$) the broad components of thestacks are shifted towards higher [OIII]/H$\beta$ and [NII]/$\alpha$ ratioscompared to the narrow component. We compare the location of the broadcomponents to shock models and find that the broad component could be due toshocks, but we do not rule out other possibilities such as the presence of anAGN. We estimate the mass loading factor (mass outflow rate/star formationrate) assuming the broad component is a photoionized outflow and find that themass loading factor increases as a function of mass which agrees with previousstudies. We show that adding emission from shocked gas to $z\sim0$ SDSS spectrashifts galaxies towards the location of $z\sim2$ galaxies on several emissionline diagnostic diagrams.

The MOSDEF Survey: Broad Emission Lines at z=1.4-3.8