scholarly journals The Bubble Nebula NGC 7635 – testing the wind-blown bubble theory

2020 ◽  
Vol 495 (3) ◽  
pp. 3041-3051
Author(s):  
J A Toalá ◽  
M A Guerrero ◽  
H Todt ◽  
L Sabin ◽  
L M Oskinova ◽  
...  

ABSTRACT We present a multiwavelength study of the iconic Bubble Nebula (NGC 7635) and its ionizing star BD+60○2522. We obtained XMM–Newton EPIC X-ray observations to search for extended X-ray emission as in other similar wind-blown bubbles around massive stars. We also obtained San Pedro Mártir spectroscopic observations with the Manchester Echelle Spectrometer to study the dynamics of the Bubble Nebula. Although our EPIC observations are deep, we do not detect extended X-ray emission from this wind-blown bubble. On the other hand, BD+60○2522 is a bright X-ray source similar to other O stars. We used the stellar atmosphere code PoWR to characterize BD+60○2522 and found that this star is a young O-type star with stellar wind capable of producing a wind-blown bubble that in principle could be filled with hot gas. We discussed our findings in line with recent numerical simulations proposing that the Bubble Nebula has been formed as the result of the fast motion of BD+60○2522 through the medium. Our kinematic study shows that the Bubble Nebula is composed by a series of nested shells, some showing blister-like structures, but with little signatures of hydrodynamical instabilities that would mix the material producing diffuse X-ray emission as seen in other wind-blown bubbles. Its morphology seems to be merely the result of projection effects of these different shells.

1998 ◽  
Vol 188 ◽  
pp. 287-288
Author(s):  
D. K. Strickland ◽  
I. R. Stevens ◽  
T. J. Ponman

Winds from massive stars and supernovae in starburst galaxies drive global outflows of hot X-ray emitting plasma, as seen in M82 and NGC 253. These galactic winds are important for understanding galaxy evolution & formation, chemical enrichment of the IGM, and the starburst phenomenon itself.X-ray observations provide the only direct probe of the hot gas in these winds. However, the limitations of current X-ray observatories and factors such as complex temperature structure, mass loading by ambient material and projection effects all make the link between the observed data and existing 1 & 2-D modeling and theory difficult to make.We have therefore begun a program of numerical simulations of galactic winds, concentrating on predicting their observable X-ray properties. We present some initial results, comparing them to the archetypal starburst wind system M82.


1991 ◽  
Vol 143 ◽  
pp. 323-334
Author(s):  
Martin Cohen

I update previous estimates of the separate contributions for radiative energy, integrated total stellar wind mass and dust mass from Wolf-Rayet stars and other massive (OBA) stars. In the context of the intriguing dusty WC9 stars, I: (1) discuss the observability (or otherwise) between 0.4 and 23 μm of the condensation route from hot gas to carbon-rich grains; (2) urge caution in the use of 10 μm infrared spectra of these luminous stars to deduce the importance of silicates as a component of the interstellar medium, and (3) speculate on a possible new method for discovering new members of this relatively rare subtype based on IRAS Low Resolution Spectra. I review the observational evidence for dust condensation around SN 1987A.


1980 ◽  
Vol 5 ◽  
pp. 541-547
Author(s):  
H. F. Henrichs

A number of massive stars of early type is found in X-ray binary systems. The catalog of Bradt et al. (1979) contains 21 sources optically identified with massive stars ranging in spectral type from 06 to B5 out of which 13 are (nearly) unevolved stars and 8 are supergiants. Single stars of this type generally show moderate to strong stellar winds. The X-rays in these binaries originate from accretion onto a compact companion (we restrict the discussion to this type of X-rays).We consider the compact star as a probe traveling through the stellar wind. This probe enables us to derive useful information about the mass outflow of massive stars.After presenting the basic data we derive an upper limit to mass loss rates of unevolved early type stars by studying X-ray pulsars. Next we consider theoretical predictions concerning the influence of X-rays on the stellar wind and compare these with the observations. Finally, using new data from IUE, we draw some conclusions about mass loss rates and velocity laws as derived from X-ray binaries.


2020 ◽  
Vol 637 ◽  
pp. A12
Author(s):  
Patrick J. Kavanagh ◽  
Manami Sasaki ◽  
Dieter Breitschwerdt ◽  
Miguel A. de Avillez ◽  
Miroslav D. Filipović ◽  
...  

Aims. We use new deep XMM-Newton observations of the northern disc of M31 to trace the hot interstellar medium (ISM) in unprecedented detail and to characterise the physical properties of the X-ray emitting plasmas. Methods. We used all XMM-Newton data up to and including our new observations to produce the most detailed image yet of the hot ISM plasma in a grand design spiral galaxy such as our own. We compared the X-ray morphology to multi-wavelength studies in the literature to set it in the context of the multi-phase ISM. We performed spectral analyses on the extended emission using our new observations as they offer sufficient depth and count statistics to constrain the plasma properties. Data from the Panchromatic Hubble Andromeda Treasury were used to estimate the energy injected by massive stars and their supernovae. We compared these results to the hot gas properties. Results. The brightest emission regions were found to be correlated with populations of massive stars, notably in the 10 kpc star-forming ring. The plasma temperatures in the ring regions are ~0.2 up to ~0.6 keV. We suggest this emission is hot ISM heated in massive stellar clusters and superbubbles. We derived X-ray luminosities, densities, and pressures for the gas in each region. We also found large extended emission filling low density gaps in the dust morphology of the northern disc, notably between the 5 and 10 kpc star-forming rings. We propose that the hot gas was heated and expelled into the gaps by the populations of massive stars in the rings. Conclusions. It is clear that the massive stellar populations are responsible for heating the ISM to X-ray emitting temperatures, filling their surroundings, and possibly driving the hot gas into the low density regions. Overall, the morphology and spectra of the hot gas in the northern disc of M31 is similar to other galaxy discs.


2016 ◽  
Vol 12 (S329) ◽  
pp. 151-155
Author(s):  
L. M. Oskinova ◽  
R. Ignace ◽  
D. P. Huenemoerder

AbstractObservations with powerful X-ray telescopes, such as XMM-Newton and Chandra, significantly advance our understanding of massive stars. Nearly all early-type stars are X-ray sources. Studies of their X-ray emission provide important diagnostics of stellar winds. High-resolution X-ray spectra of O-type stars are well explained when stellar wind clumping is taking into account, providing further support to a modern picture of stellar winds as non-stationary, inhomogeneous outflows. X-ray variability is detected from such winds, on time scales likely associated with stellar rotation. High-resolution X-ray spectroscopy indicates that the winds of late O-type stars are predominantly in a hot phase. Consequently, X-rays provide the best observational window to study these winds. X-ray spectroscopy of evolved, Wolf-Rayet type, stars allows to probe their powerful metal enhanced winds, while the mechanisms responsible for the X-ray emission of these stars are not yet understood.


2003 ◽  
Vol 212 ◽  
pp. 637-641 ◽  
Author(s):  
Dominik J. Bomans ◽  
Jörn Rossa ◽  
Kerstin Weis ◽  
Konrad Dennerl

N 51D (= DEM L 192) appears at first glance as a nearly circular, 120 pc diameter bubble of ionized gas around the LMC OB association LH 54. A deeper look reveals a complex web of filaments and deviations from radial expansion. Using a deep XMM-Newton pointing centered on N 51D we find that diffuse soft X-ray emitting gas fills the whole superbubble as delineated by the Hα filaments. Contrary to recent findings for galactic winds, the correlation between Hα and X-ray surface brightness is not good. The X-ray spectrum of this diffuse gas cannot be fitted with the LMC abundance pattern, but implies an overabundance of at least oxygen and neon, consistent with recent enrichment from supernovae Type II. Some indications for enhanced mixing at the brightest region of the Hα shell and for a beginning outflow of the hot gas were also detected.


2003 ◽  
Vol 209 ◽  
pp. 427-428
Author(s):  
Martín A. Guerrero ◽  
Robert A. Gruendl ◽  
You-Hua Chu

XMM-Newton EPIC observations of the planetary nebula NGC 7009, the Saturn Nebula, have detected extended X-ray emission from its central cavity. The diffuse X-ray emission must originate in the shocked fast stellar wind. Spectral analyses show that the temperature of the hot gas is 1.7 x 106 K. The RMS density derived from the volume emission measure is a few tens H-atom cm-3. The hot gas does not appear over-pressurized with respect to the nebular shell. The Saturn Nebula may represent an evolutionary stage at which the dynamic effects of the hot gas in the central cavity on the cold nebular shell starts to decline due to the diminishing strength of the fast stellar wind and the expansion of the central cavity.


1998 ◽  
Vol 188 ◽  
pp. 57-60
Author(s):  
H. Awaki

The Einstein observations revealed that starburst and luminous elliptical galaxies had X-ray halo. These galaxies have quite different stellar population. Starburst galaxies contain young massive stars, while elliptical galaxies generally contain an old-metal rich population dominated by K and M giants. Therefore a question is why these two type of galaxies commonly have hot gas, in spite of quite different stellar populations. In order to address this question, we observed these galaxies with ASCA. In this paper, I would like to present observational results, then compare the physical parameters of the hot gas in these galaxies.


2003 ◽  
Vol 212 ◽  
pp. 585-595 ◽  
Author(s):  
You-Hua Chu

Massive stars evolve across the H-R diagram, losing mass along the way and forming a variety of ring nebulae. During the main sequence stage, the fast stellar wind sweeps up the ambient interstellar medium to form an interstellar bubble. After a massive star evolves into a red giant or a luminous blue variable, it loses mass copiously to form a circumstellar nebula. As it evolves further into a WR star, the fast WR wind sweeps up the previous mass loss and forms a circumstellar bubble. Observations of ring nebulae around massive stars not only are fascinating, but also are useful in providing templates to diagnose the progenitors of supernovae from their circumstellar nebulae. In this review, I will summarize the characteristics of ring nebulae around massive stars throughout the H-R diagram, show recent advances in X-ray observations of bubble interiors, and compare supernovae's circumstellar nebulae with known types of ring nebulae around massive stars.


Sign in / Sign up

Export Citation Format

Share Document