| 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 | 2025-01-27 |
| Keywords | "binary characteristics separation", "chance alignments", "cepheids surveyed", "physical companions", "field stars", "star formation", "msun cepheids", "surprising characteristic", "low mass companions", "star formation theory", "initial mass function", "binary star formation", "intermediate mass stars", "XMM", "mass ratio", "`` fingerprint" |
| 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 |