The interstellar medium reveals many impressive features commonly known as ‘pillars’ or ‘globules’. These features, seen with the Hubble Space Telescope, Spitzer, and Herschel, are formed due to photoevaporation at the interface between a molecular cloud and an H II region, and are thus intimately linked to high-mass star formation. The processes by which these pillars are created, and under which conditions low- or high-mass stars form within them, are not clear.
To better understand pillar and globule formation, I started a large project in 2010, combining observations and theory. Imaging and spectroscopy observations were obtained using Herschel, Spitzer, and ground-based radiotelescopes. The idea is to study the physical properties of pillars and globules (mass, temperature, velocity structure), investigate their stellar content, and develop a theoretical model of how pillars and globules can form. The project is a collaborative effort between the institutes in Bordeaux, CEA Saclay, University of Cologne, and many others.
Our study focuses on the molecular clouds of Cygnus, Rosette, and M16, which show impressive examples of nascent and evolved pillars and globules. Data have already been taken with Herschel, SOFIA, MOPRA and other facilities, and first results from these observations and modelling have been published.
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| Herschel OT1 | SOFIA |
Schneider N., Dannhauer S., Keilmann E., et al., 2025, A&A, 704, 271
Globules and Pillars in Cygnus X IV. Velocity resolved [OI] 63 micron map of a peculiar proplyd-like object
Okada Y., Kabanovic S., Guesten R.,.., Schneider N., et al., 2024, A&A, 690, 45
Bright-rimmed clouds in IC~1396 I. Dynamics
Karim R.L., Pound M., Mundy L.G., Schneider N., et al., 2023, AJ, 166, 240
SOFIA FEEDBACK Survey: The Pillars of Creation in [CII] and Molecular Lines
Comeron F., Schneider N., Djupvik, A.A., 2022, A&A, 660, 106
Star formation in two irradiated globules around Cygnus OB2
Schneider N., Roellig M., Polehampton E.T., et al., 2021, A&A, 653, 108
Globules and Pillars in Cygnus X III. Herschel and upGREAT/SOFIA far-infrared spectroscopy of the globule IRAS
Djupvik, A.A., Comerón, F., Schneider, N., 2017, A&A, 599, 37
Globules and pillars in Cygnus X II. Massive star formation in the globule IRAS 20319+3958
Schneider, N., Bontemps, S., Motte, F., et al., 2016, A&A, 591, 40
Globules and pillars in Cygnus X I. Herschel Far-infrared imaging of the Cyg OB2 environment
Tremblin, P., Minier, V., Schneider, N. et al., 2013, A&A, 560, 19
Pillars and globules at the edges of HII regions. Confronting Herschel observations and numerical simulations
Tremblin, P., Audit, E., Minier, V., Schmidt, W., Schneider, N. 2012, A&A, 546, 33
Three-dimensional simulations of globule and pillar formation around HII regions: turbulence and shock curvature
Schneider, N., Güsten, R., Tremblin, P., et al., 2012, A&A, 542, L18
Globules and pillars seen in the [CII] 158 µm line with SOFIA
Hill, T., Motte, F., Didelon, P., White, et al., 2012, A&A, 542, 114
The M 16 molecular complex under the influence of NGC 6611. Herschel's perspective of the heating effect on the Eagle Nebula
Tremblin, P., Audit, E., Minier, V., & Schneider, N. 2012, A&A, 538, 31
3D simulations of pillar formation around HII regions: the importance of shock curvature