| Proposal ID | 072030 |
| Title | Low-Mass Companions of Cepheids: Fingerprints of Star Formation |
| Download Data Associated to the proposal | https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0720300101 |
| DOI | https://doi.org/10.5270/esa-kbghuvt |
| Principal Investigator, PI | Dr Nancy Remage Evans |
| Abstract | Star-formation theory should be able to reproduce the binary characteristics(separation, mass ratio, eccentricity) for high- and intermediate-mass stars;but first we have to define, through observations, what those characteristicsare. This project proposes XMM X-ray observations of a sample of 8 possiblecompanions of 5 Msun Cepheids to confirm that they are young physicalcompanions, not chance alignments with field stars. The sample is a subset of 69Cepheids surveyed with the Hubble Space Telescope Wide Field Camera 3 (WFC3),identifying 35 possible low-mass companions. They have the surprisingcharacteristic that there are more F-G dwarfs (compared to K dwarfs) thanpredicted by the Initial Mass Function, a fingerprint of binary star formation |
| Publications |
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| Instrument | EMOS1, EMOS2, EPN, OM, RGS1, RGS2 |
| Temporal Coverage | 2013-08-20T21:52:30Z/2014-01-27T01:00:47Z |
| Version | PPS_NOT_AVAILABLE |
| Mission Description | The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earths atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis. |
| Creator Contact | https://www.cosmos.esa.int/web/xmm-newton/xmm-newton-helpdesk |
| Date Published | 2015-02-10T23:00:00Z |
| Last Update | 2025-08-04 |
| Keywords | "XMM", "low mass companions", "intermediate mass stars", "mass ratio", "field stars", "initial mass function", "physical companions", "cepheids surveyed", "binary characteristics separation", "msun cepheids", "chance alignments", "`` fingerprint", "star formation theory", "star formation", "surprising characteristic", "binary star formation" |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, Dr Nancy Remage Evans, 2015, 'Low-Mass Companions of Cepheids: Fingerprints of Star Formation', PPS_NOT_AVAILABLE, European Space Agency, https://doi.org/10.5270/esa-kbghuvt |