Low-excitation blobs in the Magellanic Clouds

¹ LERMA, Observatoire de Paris, 61 avenue de l'Observatoire, 75014 Paris, France e-mail: Frederic.Meynadier@obspm.fr
² UPMC - Université Paris 6, 4 place Jussieu, 75005 Paris, France

Received: 7 July 2006
Accepted: 15 September 2006

Abstract

Aims.We study an unknown, or very poorly known, interstellar H ii component in the Magellanic Clouds. This is the first study ever devoted to this class of objects, which we call low-excitation blobs (LEBs).

Methods.We used low-dispersion spectroscopy carried out at ESO to obtain emission line intensities of , , and  ( 4959 + 5007) for 15 objects in the Large Magellanic Cloud and 14 objects in the Small Magellanic Cloud. Results are displayed in excitation (/ ratio) versus luminosity diagrams.

Results.We show the presence of an LEB component in the Magellanic Clouds and study its relationship with the already known class of high-excitation blobs (HEBs). The newly found LEBs are lower excitation counterparts of HEBs and are powered by less massive exciting stars. Further study of LEBs is expected to provide new pieces of information for a better understanding the low mass end of the upper initial mass function in the Magellanic Clouds.