Juri Poutanen

Equation of state constraints for the cold dense matter inside neutron stars using the cooling tail method

The cooling phase of thermonuclear (type-I) X-ray bursts can be used to constrain the neutron star (NS) compactness by comparing the observed cooling tracks of bursts to accurate theoretical atmosphere model calculations. By applying the so-called cooling tail method, where the information from the whole cooling track is used, we constrain the mass, radius, and distance for three different NSs in low-mass X-ray binaries 4U 1702-429, 4U 1724-307, and SAX J1810.8-260. Care is taken to only use the hard state bursts where it is thought that only the NS surface alone is emitting. We then utilize a Markov chain Monte Carlo algorithm within a Bayesian framework to obtain a parameterized equation of state (EoS) of cold dense matter from our initial mass and radius constraints. This allows us to set limits on various nuclear parameters and to constrain an empirical pressure-density relation for the dense matter. Our predicted EoS results in NS radius between 10.5-12.8 km (95% confidence limits) for a mass of 1.4

Propeller effect in two brightest transient X-ray pulsars: 4U 0115+63 and V 0332+53

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Positive correlation between the cyclotron line energy and luminosity in sub-critical X-ray pulsars: Doppler effect in the accretion channel

. Due to systematic errors and uncertainty in the composition these results should be interpreted as lower limits for the radius.

Luminosity dependence of the cyclotron line and evidence for the accretion regime transition in V 0332+53

We present the results of the monitoring programmes performed with the Swift/XRT telescope and aimed specifically to detect an abrupt decrease of the observed flux associated with a transition to the propeller regime in two well known X-ray pulsars 4U 0115+63 and V 0332+53 during their giant outbursts in 2015. Such transitions were detected at the threshold luminosities of

Measuring the basic parameters of neutron stars using model atmospheres

(1.4pm0.4)times10^{36}

PROPELLER EFFECT in the TRANSIENT X-RAY PULSAR SMC X-2

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Detection of burning ashes from thermonuclear X-ray bursts

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Super-Eddington accretion on to a magnetized neutron star

and

The X-ray properties of Be/X-ray pulsars in quiescence

(2.0pm0.4)times10^{36}

Neutron star mass and radius measurements from atmospheric model fits to X-ray burst cooling tail spectra

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