The Hubble diagram of type Ia supernovae as a function of host galaxy morphology

• DOI: 10.1046/j.1365-8711.2003.06312.x
• Publication Date: 2004-12-28T02:53:50Z
• Authors: M. Sullivan; R. S. Ellis; G. Aldering; R. Amanullah; P. Astier; G. Blanc; M. S. Burns; A. Conley; S. E. Deustua; M. Doi; S. Fabbro; G. Folatelli; A. S. Fruchter; G. Garavini; R. Gibbons; G. Goldhaber; A. Goobar; D. E. Groom; D. Hardin; I. Hook; D. A. Howell; M. Irwin; A. G. Kim; R. A. Knop; C. Lidman; R. McMahon; J. Mendez; S. Nobili; P. E. Nugent; R. Pain; N. Panagia; C. R. Pennypacker; S. Perlmutter; R. Quimby; J. Raux; N. Regnault; P. Ruiz-Lapuente; B. Schaefer; K. Schahmaneche; A. L. Spadafora; N. A. Walton; L. Wang; W. M. Wood-Vasey; N. Yasuda
• Keywords: Extinction (optical mineralogy); Cosmic distance ladder

We present new results on the Hubble diagram of distant type Ia supernovae (SNe Ia) segregated according to host galaxy. This makes it possible check earlier evidence for a cosmological constant by explicitly comparing SNe residing in galaxies likely contain negligible dust with larger sample. The parameters derived from these hosted presumed dust-free early-type support claims constant, which we demonstrate at ≃5σ significance, and internal extinction implied is small even late-type systems (AB < 0.2). Thus, our data that galaxy unlikely systematically dim manner would produce spurious constant. Our analysis based Space Telescope STIS 'snapshot' images Keck-II echellette spectroscopy locations SNe, spanning redshift range 0 z 0.8. Selecting sample discovered Supernova Cosmology Project (SCP), classify 39 using combination imaging, Keck ground-based broad-band photometry. are analysed comparison low-redshift 25 re-calibrated precepts SCP. scatter observed diagrams correlates closely morphology. find this smallest occurring hosts largest those galaxies. Moreover, appear ≃ 0.14 ± 0.09 mag fainter their light-curve-width-corrected luminosity than hosts, as expected if modest amount contributing factor. As previous studies, broadly independent whether corrections upon SN light-curve shapes performed. also use high-redshift set search morphological dependences light curves, sometimes seen samples. No significant trends found, possibly because widths too limited.