Details

Autor(en) / Beteiligte

• Pearson, W. J.
• Pistis, F.
• Figueira, M.
• Małek, K.
• Moutard, T.
• Vergani, D.
• Pollo, A.

Titel

Influence of star-forming galaxy selection on the galaxy main sequence

Ist Teil von

• Astronomy and astrophysics (Berlin), 2023-11, Vol.679, p.A35

Ort / Verlag

Heidelberg: EDP Sciences

Erscheinungsjahr

2023

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Aims. This work aims to determine how the galaxy main sequence (MS) changes using seven different commonly used methods to select the star-forming galaxies within VIPERS data over 0.5 ≤  z  < 1.2. The form and redshift evolution of the MS was then compared between selection methods. Methods. The star-forming galaxies were selected using widely known methods: a specific star-formation rate (sSFR); Baldwin, Phillips, and Terlevich (BPT) diagram; a 4000 Å spectral break (D4000) cut; and four colour-colour cuts (near-ultra-violet – V verses r  −  J (NUVrJ), near-ultra-violet – V verses r  −  K (NUVrK), u  −  r , and U  −  V verses V  −  J (UVJ)). The main sequences were then fitted for each of the seven selection methods using a Markov chain Monte Carlo forward modelling routine, fitting both a linear main sequence and a MS with a high-mass turnover to the star-forming galaxies. This was done in four redshift bins of 0.50 ≤  z  < 0.62, 0.62 ≤  z  < 0.72, 0.72 ≤  z  < 0.85, and 0.85 ≤  z  < 1.20. Results. The slopes of all star-forming samples were found to either remain constant or increase with redshift, and the scatters were approximately constant. There is no clear redshift dependency of the presence of a high-mass turnover for the majority of samples, with the NUVrJ and NUVrK being the only samples with turnovers only at low redshift. No samples have turnovers at all redshifts. Star-forming galaxies selected with sSFR and u  −  r are the only samples to have no high-mass turnover in all redshift bins. The normalisation of the MS increases with redshift, as expected. The scatter around the MS is lower than the ≈0.3 dex typically seen in MS studies for all seven samples. Conclusions. The lack (or presence) of a high-mass turnover is at least partially a result of the method used to select star-forming galaxies. However, whether a turnover should be present or not is unclear.