Bibcode
DOI
Knapen, Johan H.; Beckman, John E.; Cepa, Jordi; van der Hulst, Thijs; Rand, Richard J.
Referencia bibliográfica
Astrophysical Journal, Part 2 - Letters (ISSN 0004-637X), vol. 385, Feb. 1, 1992, p. L37-L40. Research supported by DGICYT and EEC.
Fecha de publicación:
2
1992
Revista
Número de citas
55
Número de citas referidas
49
Descripción
The distribution of ionized, molecular, and atomic hydrogen in the disk
and especially along the spiral arms of the Whirlpool galaxy, M51, is
investigated by combining recently published maps of the H-alpha, H2,
and H I surface densities, and a twofold result is reported. The
existence is established of a symmetric pattern of peaks and dips in the
arm/interarm ratio of the massive star formation efficiency along the
two main arms, similar to the patterns previously found in NGC 3992 and
NGC 628. The pattern is due to enhanced on-arm star formation at
specific radii in the disk. They correspond to antiresonances of a
density wave system, suggesting that the resonance pattern locally
affects the process of star formation. The high peaks in the H-alpha
distribution along the arms are not reproduced in H2 - by far the most
abundant form of neutral hydrogen in the inner disk. It is argued that
the peaks do show up, although less strongly in the H I surface density
along the arms.